diff --git a/packages/backend/src/boot/entry.ts b/packages/backend/src/boot/entry.ts
index 735a0f4666..e52d77ab9b 100644
--- a/packages/backend/src/boot/entry.ts
+++ b/packages/backend/src/boot/entry.ts
@@ -9,6 +9,7 @@
 
 import cluster from 'node:cluster';
 import { EventEmitter } from 'node:events';
+import { inspect } from 'node:util';
 import chalk from 'chalk';
 import Xev from 'xev';
 import Logger from '@/logger.js';
@@ -53,15 +54,22 @@ async function main() {
 
 	// Display detail of unhandled promise rejection
 	if (!envOption.quiet) {
-		process.on('unhandledRejection', console.dir);
+		process.on('unhandledRejection', e => {
+			try {
+				logger.error('Unhandled rejection:', inspect(e));
+			} catch {
+				console.error('Unhandled rejection:', inspect(e));
+			}
+		});
 	}
 
 	// Display detail of uncaught exception
 	process.on('uncaughtException', err => {
 		try {
-			logger.error(err);
-			console.trace(err);
-		} catch { }
+			logger.error('Uncaught exception:', err);
+		} catch {
+			console.error('Uncaught exception:', err);
+		}
 	});
 
 	// Dying away...
diff --git a/packages/backend/src/boot/master.ts b/packages/backend/src/boot/master.ts
index 538c529106..301db03e0e 100644
--- a/packages/backend/src/boot/master.ts
+++ b/packages/backend/src/boot/master.ts
@@ -172,7 +172,7 @@ function loadConfigBoot(): Config {
 		config = loadConfig();
 	} catch (exception) {
 		if (typeof exception === 'string') {
-			configLogger.error(exception);
+			configLogger.error('Exception loading config:', exception);
 			process.exit(1);
 		} else if ((exception as any).code === 'ENOENT') {
 			configLogger.error('Configuration file not found', null, true);
diff --git a/packages/backend/src/core/DriveService.ts b/packages/backend/src/core/DriveService.ts
index 73125f36d7..e1e74d0868 100644
--- a/packages/backend/src/core/DriveService.ts
+++ b/packages/backend/src/core/DriveService.ts
@@ -46,6 +46,7 @@ import { ModerationLogService } from '@/core/ModerationLogService.js';
 import { UtilityService } from '@/core/UtilityService.js';
 import { BunnyService } from '@/core/BunnyService.js';
 import { LoggerService } from './LoggerService.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 
 type AddFileArgs = {
 	/** User who wish to add file */
@@ -311,7 +312,7 @@ export class DriveService {
 					thumbnail,
 				};
 			} catch (err) {
-				this.registerLogger.warn(`GenerateVideoThumbnail failed: ${err}`);
+				this.registerLogger.warn(`GenerateVideoThumbnail failed: ${renderInlineError(err)}`);
 				return {
 					webpublic: null,
 					thumbnail: null,
@@ -344,7 +345,7 @@ export class DriveService {
 			metadata.height && metadata.height <= 2048
 			);
 		} catch (err) {
-			this.registerLogger.warn(`sharp failed: ${err}`);
+			this.registerLogger.warn(`sharp failed: ${renderInlineError(err)}`);
 			return {
 				webpublic: null,
 				thumbnail: null,
@@ -651,7 +652,7 @@ export class DriveService {
 						userId: user ? user.id : IsNull(),
 					}) as MiDriveFile;
 				} else {
-					this.registerLogger.error(err as Error);
+					this.registerLogger.error('Error in drive register', err as Error);
 					throw err;
 				}
 			}
@@ -895,7 +896,7 @@ export class DriveService {
 			this.downloaderLogger.succ(`Got: ${driveFile.id}`);
 			return driveFile!;
 		} catch (err) {
-			this.downloaderLogger.error(`Failed to create drive file: ${err}`, {
+			this.downloaderLogger.error(`Failed to create drive file: ${renderInlineError(err)}`, {
 				url: url,
 				e: err,
 			});
diff --git a/packages/backend/src/core/FetchInstanceMetadataService.ts b/packages/backend/src/core/FetchInstanceMetadataService.ts
index 980f1fcacf..9f745f9459 100644
--- a/packages/backend/src/core/FetchInstanceMetadataService.ts
+++ b/packages/backend/src/core/FetchInstanceMetadataService.ts
@@ -15,6 +15,7 @@ import { LoggerService } from '@/core/LoggerService.js';
 import { HttpRequestService } from '@/core/HttpRequestService.js';
 import { bindThis } from '@/decorators.js';
 import { FederatedInstanceService } from '@/core/FederatedInstanceService.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import type { CheerioAPI } from 'cheerio';
 
 type NodeInfo = {
@@ -130,7 +131,7 @@ export class FetchInstanceMetadataService {
 
 			this.logger.succ(`Successfuly updated metadata of ${instance.host}`);
 		} catch (e) {
-			this.logger.error(`Failed to update metadata of ${instance.host}: ${e}`);
+			this.logger.error(`Failed to update metadata of ${instance.host}: ${renderInlineError(e)}`);
 		} finally {
 			await this.unlock(host);
 		}
diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index 097d657ba3..3703926781 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -549,8 +549,6 @@ export class NoteCreateService implements OnApplicationShutdown {
 				throw err;
 			}
 
-			console.error(e);
-
 			throw e;
 		}
 	}
diff --git a/packages/backend/src/core/WebAuthnService.ts b/packages/backend/src/core/WebAuthnService.ts
index 372e1e2ab7..1b75811fff 100644
--- a/packages/backend/src/core/WebAuthnService.ts
+++ b/packages/backend/src/core/WebAuthnService.ts
@@ -17,6 +17,8 @@ import type { Config } from '@/config.js';
 import { bindThis } from '@/decorators.js';
 import { MiUser } from '@/models/_.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
+import { LoggerService } from '@/core/LoggerService.js';
+import Logger from '@/logger.js';
 import type {
 	AuthenticationResponseJSON,
 	AuthenticatorTransportFuture,
@@ -28,6 +30,8 @@ import type {
 
 @Injectable()
 export class WebAuthnService {
+	private readonly logger: Logger;
+
 	constructor(
 		@Inject(DI.config)
 		private config: Config,
@@ -40,7 +44,9 @@ export class WebAuthnService {
 
 		@Inject(DI.userSecurityKeysRepository)
 		private userSecurityKeysRepository: UserSecurityKeysRepository,
+		loggerService: LoggerService,
 	) {
+		this.logger = loggerService.getLogger('web-authn');
 	}
 
 	@bindThis
@@ -114,7 +120,7 @@ export class WebAuthnService {
 				requireUserVerification: true,
 			});
 		} catch (error) {
-			console.error(error);
+			this.logger.error(error as Error, 'Error authenticating webauthn');
 			throw new IdentifiableError('5c1446f8-8ca7-4d31-9f39-656afe9c5d87', 'verification failed');
 		}
 
@@ -301,7 +307,7 @@ export class WebAuthnService {
 				requireUserVerification: true,
 			});
 		} catch (error) {
-			console.error(error);
+			this.logger.error(error as Error, 'Error authenticating webauthn');
 			throw new IdentifiableError('b18c89a7-5b5e-4cec-bb5b-0419f332d430', 'verification failed');
 		}
 
diff --git a/packages/backend/src/core/WebfingerService.ts b/packages/backend/src/core/WebfingerService.ts
index f57e7a2c1f..664963f3a3 100644
--- a/packages/backend/src/core/WebfingerService.ts
+++ b/packages/backend/src/core/WebfingerService.ts
@@ -9,6 +9,7 @@ import { XMLParser } from 'fast-xml-parser';
 import { HttpRequestService } from '@/core/HttpRequestService.js';
 import { bindThis } from '@/decorators.js';
 import type Logger from '@/logger.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { RemoteLoggerService } from './RemoteLoggerService.js';
 
 export type ILink = {
@@ -109,7 +110,7 @@ export class WebfingerService {
 			const template = (hostMeta['XRD']['Link'] as Array<any>).filter(p => p['@_rel'] === 'lrdd')[0]['@_template'];
 			return template.indexOf('{uri}') < 0 ? null : template;
 		} catch (err) {
-			this.logger.error(`error while request host-meta for ${url}: ${err}`);
+			this.logger.error(`error while request host-meta for ${url}: ${renderInlineError(err)}`);
 			return null;
 		}
 	}
diff --git a/packages/backend/src/core/activitypub/ApInboxService.ts b/packages/backend/src/core/activitypub/ApInboxService.ts
index 0ffe0eea92..f4208b6e93 100644
--- a/packages/backend/src/core/activitypub/ApInboxService.ts
+++ b/packages/backend/src/core/activitypub/ApInboxService.ts
@@ -32,6 +32,7 @@ import { AbuseReportService } from '@/core/AbuseReportService.js';
 import { FederatedInstanceService } from '@/core/FederatedInstanceService.js';
 import { fromTuple } from '@/misc/from-tuple.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import InstanceChart from '@/core/chart/charts/instance.js';
 import FederationChart from '@/core/chart/charts/federation.js';
 import { FetchInstanceMetadataService } from '@/core/FetchInstanceMetadataService.js';
@@ -127,7 +128,7 @@ export class ApInboxService {
 					results.push([id, result]);
 				} catch (err) {
 					if (err instanceof Error || typeof err === 'string') {
-						this.logger.error(err);
+						this.logger.error(`Unhandled error in activity ${getNullableApId(item || 'undefined')}:`, err);
 					} else {
 						throw err;
 					}
@@ -253,7 +254,7 @@ export class ApInboxService {
 		resolver ??= this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(err => {
-			this.logger.error(`Resolution failed: ${err}`);
+			this.logger.error(`Resolution failed: ${renderInlineError(err)}`);
 			throw err;
 		});
 
@@ -326,7 +327,7 @@ export class ApInboxService {
 		if (targetUri.startsWith('bear:')) return 'skip: bearcaps url not supported.';
 
 		const target = await resolver.secureResolve(activityObject, uri).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${renderInlineError(e)}`);
 			throw e;
 		});
 
@@ -499,7 +500,7 @@ export class ApInboxService {
 		resolver ??= this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activityObject).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${renderInlineError(e)}`);
 			throw e;
 		});
 
@@ -668,7 +669,7 @@ export class ApInboxService {
 		resolver ??= this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${renderInlineError(e)}`);
 			throw e;
 		});
 
@@ -740,7 +741,7 @@ export class ApInboxService {
 		resolver ??= this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${renderInlineError(e)}`);
 			throw e;
 		});
 
@@ -872,7 +873,7 @@ export class ApInboxService {
 		resolver ??= this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${renderInlineError(e)}`);
 			throw e;
 		});
 
diff --git a/packages/backend/src/core/activitypub/models/ApNoteService.ts b/packages/backend/src/core/activitypub/models/ApNoteService.ts
index 5b66031bee..5b3def4bc3 100644
--- a/packages/backend/src/core/activitypub/models/ApNoteService.ts
+++ b/packages/backend/src/core/activitypub/models/ApNoteService.ts
@@ -26,6 +26,7 @@ import { bindThis } from '@/decorators.js';
 import { checkHttps } from '@/misc/check-https.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
 import { isRetryableError } from '@/misc/is-retryable-error.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { getOneApId, getApId, validPost, isEmoji, getApType, isApObject, isDocument, IApDocument } from '../type.js';
 import { ApLoggerService } from '../ApLoggerService.js';
 import { ApMfmService } from '../ApMfmService.js';
@@ -161,7 +162,7 @@ export class ApNoteService {
 		const entryUri = getApId(value);
 		const err = this.validateNote(object, entryUri, actor);
 		if (err) {
-			this.logger.error(err.message, {
+			this.logger.error(`Error creating note: ${renderInlineError(err)}`, {
 				resolver: { history: resolver.getHistory() },
 				value,
 				object,
@@ -269,14 +270,14 @@ export class ApNoteService {
 			? await this.resolveNote(note.inReplyTo, { resolver })
 				.then(x => {
 					if (x == null) {
-						this.logger.warn('Specified inReplyTo, but not found');
+						this.logger.warn(`Specified inReplyTo "${note.inReplyTo}", but not found`);
 						throw new Error(`could not fetch inReplyTo ${note.inReplyTo} for note ${entryUri}`);
 					}
 
 					return x;
 				})
 				.catch(async err => {
-					this.logger.warn(`error ${err.statusCode ?? err} fetching inReplyTo ${note.inReplyTo} for note ${entryUri}`);
+					this.logger.warn(`error ${renderInlineError(err)} fetching inReplyTo ${note.inReplyTo} for note ${entryUri}`);
 					throw err;
 				})
 			: null;
@@ -379,7 +380,7 @@ export class ApNoteService {
 		const entryUri = getApId(value);
 		const err = this.validateNote(object, entryUri, actor, user);
 		if (err) {
-			this.logger.error(err.message, {
+			this.logger.error(`Error updating note: ${renderInlineError(err)}`, {
 				resolver: { history: resolver.getHistory() },
 				value,
 				object,
@@ -473,14 +474,14 @@ export class ApNoteService {
 			? await this.resolveNote(note.inReplyTo, { resolver })
 				.then(x => {
 					if (x == null) {
-						this.logger.warn('Specified inReplyTo, but not found');
+						this.logger.warn(`Specified inReplyTo "${note.inReplyTo}", but not found`);
 						throw new Error(`could not fetch inReplyTo ${note.inReplyTo} for note ${entryUri}`);
 					}
 
 					return x;
 				})
 				.catch(async err => {
-					this.logger.warn(`error ${err.statusCode ?? err} fetching inReplyTo ${note.inReplyTo} for note ${entryUri}`);
+					this.logger.warn(`error ${renderInlineError(err)} fetching inReplyTo ${note.inReplyTo} for note ${entryUri}`);
 					throw err;
 				})
 			: null;
@@ -685,18 +686,13 @@ export class ApNoteService {
 				const quote = await this.resolveNote(uri, { resolver });
 
 				if (quote == null) {
-					this.logger.warn(`Failed to resolve quote "${uri}" for note "${entryUri}": request error`);
+					this.logger.warn(`Failed to resolve quote "${uri}" for note "${entryUri}": fetch failed`);
 					return false;
 				}
 
 				return quote;
 			} catch (e) {
-				if (e instanceof Error) {
-					this.logger.warn(`Failed to resolve quote "${uri}" for note "${entryUri}":`, e);
-				} else {
-					this.logger.warn(`Failed to resolve quote "${uri}" for note "${entryUri}": ${e}`);
-				}
-
+				this.logger.warn(`Failed to resolve quote "${uri}" for note "${entryUri}": ${renderInlineError(e)}`);
 				return isRetryableError(e);
 			}
 		};
diff --git a/packages/backend/src/queue/processors/ExportAccountDataProcessorService.ts b/packages/backend/src/queue/processors/ExportAccountDataProcessorService.ts
index 33a2362c4a..9caf5409dc 100644
--- a/packages/backend/src/queue/processors/ExportAccountDataProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportAccountDataProcessorService.ts
@@ -22,6 +22,7 @@ import { Packed } from '@/misc/json-schema.js';
 import { UtilityService } from '@/core/UtilityService.js';
 import { DownloadService } from '@/core/DownloadService.js';
 import { EmailService } from '@/core/EmailService.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type * as Bull from 'bullmq';
 
@@ -113,7 +114,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				userStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing user:', err);
 						rej(err);
 					} else {
 						res();
@@ -145,7 +146,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				profileStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing profile:', err);
 						rej(err);
 					} else {
 						res();
@@ -179,7 +180,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				ipStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing IPs:', err);
 						rej(err);
 					} else {
 						res();
@@ -214,7 +215,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				notesStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing notes:', err);
 						rej(err);
 					} else {
 						res();
@@ -275,7 +276,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				followingStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing following:', err);
 						rej(err);
 					} else {
 						res();
@@ -345,7 +346,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				followerStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing followers:', err);
 						rej(err);
 					} else {
 						res();
@@ -406,7 +407,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				filesStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing drive:', err);
 						rej(err);
 					} else {
 						res();
@@ -432,7 +433,7 @@ export class ExportAccountDataProcessorService {
 				await this.downloadService.downloadUrl(file.url, filePath);
 				downloaded = true;
 			} catch (e) {
-				this.logger.error(e instanceof Error ? e : new Error(e as string));
+				this.logger.error(`Error writing drive file ${file.id} (${file.name}): ${renderInlineError(e)}`);
 			}
 
 			if (!downloaded) {
@@ -464,7 +465,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				mutingStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing mutings:', err);
 						rej(err);
 					} else {
 						res();
@@ -527,7 +528,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				blockingStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing blockings:', err);
 						rej(err);
 					} else {
 						res();
@@ -589,7 +590,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				favoriteStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing favorites:', err);
 						rej(err);
 					} else {
 						res();
@@ -650,7 +651,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				antennaStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing antennas:', err);
 						rej(err);
 					} else {
 						res();
@@ -708,7 +709,7 @@ export class ExportAccountDataProcessorService {
 			return new Promise<void>((res, rej) => {
 				listStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error writing lists:', err);
 						rej(err);
 					} else {
 						res();
diff --git a/packages/backend/src/queue/processors/ExportAntennasProcessorService.ts b/packages/backend/src/queue/processors/ExportAntennasProcessorService.ts
index b3111865ad..3d3a32a597 100644
--- a/packages/backend/src/queue/processors/ExportAntennasProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportAntennasProcessorService.ts
@@ -53,7 +53,7 @@ export class ExportAntennasProcessorService {
 			return new Promise((resolve, reject) => {
 				stream.write(input, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error exporting antennas:', err);
 						reject();
 					} else {
 						resolve();
diff --git a/packages/backend/src/queue/processors/ExportBlockingProcessorService.ts b/packages/backend/src/queue/processors/ExportBlockingProcessorService.ts
index ecc439db69..764bd062a7 100644
--- a/packages/backend/src/queue/processors/ExportBlockingProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportBlockingProcessorService.ts
@@ -87,7 +87,7 @@ export class ExportBlockingProcessorService {
 					await new Promise<void>((res, rej) => {
 						stream.write(content + '\n', err => {
 							if (err) {
-								this.logger.error(err);
+								this.logger.error('Error exporting blocking:', err);
 								rej(err);
 							} else {
 								res();
diff --git a/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts b/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts
index 14d32e78b3..09ed0bfa56 100644
--- a/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts
@@ -66,7 +66,7 @@ export class ExportCustomEmojisProcessorService {
 			return new Promise<void>((res, rej) => {
 				metaStream.write(text, err => {
 					if (err) {
-						this.logger.error(err);
+						this.logger.error('Error exporting custom emojis:', err);
 						rej(err);
 					} else {
 						res();
@@ -101,7 +101,7 @@ export class ExportCustomEmojisProcessorService {
 				await this.downloadService.downloadUrl(emoji.originalUrl, emojiPath);
 				downloaded = true;
 			} catch (e) { // TODO: 何度か再試行
-				this.logger.error(e instanceof Error ? e : new Error(e as string));
+				this.logger.error('Error exporting custom emojis:', e as Error);
 			}
 
 			if (!downloaded) {
diff --git a/packages/backend/src/queue/processors/ExportFavoritesProcessorService.ts b/packages/backend/src/queue/processors/ExportFavoritesProcessorService.ts
index b81feece01..32fcb5d4bc 100644
--- a/packages/backend/src/queue/processors/ExportFavoritesProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportFavoritesProcessorService.ts
@@ -64,7 +64,7 @@ export class ExportFavoritesProcessorService {
 				return new Promise<void>((res, rej) => {
 					stream.write(text, err => {
 						if (err) {
-							this.logger.error(err);
+							this.logger.error('Error exporting favorites:', err);
 							rej(err);
 						} else {
 							res();
diff --git a/packages/backend/src/queue/processors/ExportFollowingProcessorService.ts b/packages/backend/src/queue/processors/ExportFollowingProcessorService.ts
index 903f962515..0b001dce75 100644
--- a/packages/backend/src/queue/processors/ExportFollowingProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportFollowingProcessorService.ts
@@ -98,7 +98,7 @@ export class ExportFollowingProcessorService {
 					await new Promise<void>((res, rej) => {
 						stream.write(content + '\n', err => {
 							if (err) {
-								this.logger.error(err);
+								this.logger.error('Error exporting following:', err);
 								rej(err);
 							} else {
 								res();
diff --git a/packages/backend/src/queue/processors/ExportMutingProcessorService.ts b/packages/backend/src/queue/processors/ExportMutingProcessorService.ts
index f9867ade29..9b12269401 100644
--- a/packages/backend/src/queue/processors/ExportMutingProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportMutingProcessorService.ts
@@ -88,7 +88,7 @@ export class ExportMutingProcessorService {
 					await new Promise<void>((res, rej) => {
 						stream.write(content + '\n', err => {
 							if (err) {
-								this.logger.error(err);
+								this.logger.error('Error exporting mutings:', err);
 								rej(err);
 							} else {
 								res();
diff --git a/packages/backend/src/queue/processors/ExportUserListsProcessorService.ts b/packages/backend/src/queue/processors/ExportUserListsProcessorService.ts
index c483d79854..5483f1d47e 100644
--- a/packages/backend/src/queue/processors/ExportUserListsProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportUserListsProcessorService.ts
@@ -74,7 +74,7 @@ export class ExportUserListsProcessorService {
 					await new Promise<void>((res, rej) => {
 						stream.write(content + '\n', err => {
 							if (err) {
-								this.logger.error(err);
+								this.logger.error('Error exporting lists:', err);
 								rej(err);
 							} else {
 								res();
diff --git a/packages/backend/src/queue/processors/ImportAntennasProcessorService.ts b/packages/backend/src/queue/processors/ImportAntennasProcessorService.ts
index 9c033b73e2..901bf5f70a 100644
--- a/packages/backend/src/queue/processors/ImportAntennasProcessorService.ts
+++ b/packages/backend/src/queue/processors/ImportAntennasProcessorService.ts
@@ -73,7 +73,7 @@ export class ImportAntennasProcessorService {
 			for (const antenna of job.data.antenna) {
 				if (antenna.keywords.length === 0 || antenna.keywords[0].every(x => x === '')) continue;
 				if (!validate(antenna)) {
-					this.logger.warn('Validation Failed');
+					this.logger.warn('Antenna validation failed');
 					continue;
 				}
 				const result = await this.antennasRepository.insertOne({
@@ -96,7 +96,7 @@ export class ImportAntennasProcessorService {
 				this.globalEventService.publishInternalEvent('antennaCreated', result);
 			}
 		} catch (err: any) {
-			this.logger.error(err);
+			this.logger.error('Error importing antennas:', err);
 		}
 	}
 }
diff --git a/packages/backend/src/queue/processors/ImportBlockingProcessorService.ts b/packages/backend/src/queue/processors/ImportBlockingProcessorService.ts
index b78229c648..707bf093fc 100644
--- a/packages/backend/src/queue/processors/ImportBlockingProcessorService.ts
+++ b/packages/backend/src/queue/processors/ImportBlockingProcessorService.ts
@@ -97,7 +97,7 @@ export class ImportBlockingProcessorService {
 
 			this.queueService.createBlockJob([{ from: { id: user.id }, to: { id: target.id }, silent: true }]);
 		} catch (e) {
-			this.logger.warn(`Error: ${e}`);
+			this.logger.error('Error importing blockings:', e as Error);
 		}
 	}
 }
diff --git a/packages/backend/src/queue/processors/ImportCustomEmojisProcessorService.ts b/packages/backend/src/queue/processors/ImportCustomEmojisProcessorService.ts
index d08cadd378..4f54873924 100644
--- a/packages/backend/src/queue/processors/ImportCustomEmojisProcessorService.ts
+++ b/packages/backend/src/queue/processors/ImportCustomEmojisProcessorService.ts
@@ -16,6 +16,7 @@ import { DriveService } from '@/core/DriveService.js';
 import { DownloadService } from '@/core/DownloadService.js';
 import { bindThis } from '@/decorators.js';
 import type { Config } from '@/config.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type * as Bull from 'bullmq';
 import type { DbUserImportJobData } from '../types.js';
@@ -65,7 +66,7 @@ export class ImportCustomEmojisProcessorService {
 			await this.downloadService.downloadUrl(file.url, destPath, { operationTimeout: this.config.import?.downloadTimeout, maxSize: this.config.import?.maxFileSize });
 		} catch (e) { // TODO: 何度か再試行
 			if (e instanceof Error || typeof e === 'string') {
-				this.logger.error(e);
+				this.logger.error('Error importing custom emojis:', e as Error);
 			}
 			throw e;
 		}
@@ -117,7 +118,7 @@ export class ImportCustomEmojisProcessorService {
 					});
 				} catch (e) {
 					if (e instanceof Error || typeof e === 'string') {
-						this.logger.error(`couldn't import ${emojiPath} for ${emojiInfo.name}: ${e}`);
+						this.logger.error(`couldn't import ${emojiPath} for ${emojiInfo.name}: ${renderInlineError(e)}`);
 					}
 					continue;
 				}
@@ -127,9 +128,7 @@ export class ImportCustomEmojisProcessorService {
 
 			this.logger.succ('Imported');
 		} catch (e) {
-			if (e instanceof Error || typeof e === 'string') {
-				this.logger.error(e);
-			}
+			this.logger.error('Error importing custom emojis:', e as Error);
 			cleanup();
 			throw e;
 		}
diff --git a/packages/backend/src/queue/processors/ImportFollowingProcessorService.ts b/packages/backend/src/queue/processors/ImportFollowingProcessorService.ts
index 70c9f3a096..647faa142b 100644
--- a/packages/backend/src/queue/processors/ImportFollowingProcessorService.ts
+++ b/packages/backend/src/queue/processors/ImportFollowingProcessorService.ts
@@ -97,7 +97,7 @@ export class ImportFollowingProcessorService {
 
 			this.queueService.createFollowJob([{ from: user, to: { id: target.id }, silent: true, withReplies: job.data.withReplies }]);
 		} catch (e) {
-			this.logger.warn(`Error: ${e}`);
+			this.logger.error('Error importing followings:', e as Error);
 		}
 	}
 }
diff --git a/packages/backend/src/queue/processors/ImportMutingProcessorService.ts b/packages/backend/src/queue/processors/ImportMutingProcessorService.ts
index ec9d2b6c4c..8b90f7663b 100644
--- a/packages/backend/src/queue/processors/ImportMutingProcessorService.ts
+++ b/packages/backend/src/queue/processors/ImportMutingProcessorService.ts
@@ -14,6 +14,7 @@ import { DownloadService } from '@/core/DownloadService.js';
 import { UserMutingService } from '@/core/UserMutingService.js';
 import { UtilityService } from '@/core/UtilityService.js';
 import { bindThis } from '@/decorators.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type * as Bull from 'bullmq';
 import type { DbUserImportJobData } from '../types.js';
@@ -92,7 +93,7 @@ export class ImportMutingProcessorService {
 
 				await this.userMutingService.mute(user, target);
 			} catch (e) {
-				this.logger.warn(`Error in line:${linenum} ${e}`);
+				this.logger.warn(`Error in line:${linenum} ${renderInlineError(e)}`);
 			}
 		}
 
diff --git a/packages/backend/src/queue/processors/ImportNotesProcessorService.ts b/packages/backend/src/queue/processors/ImportNotesProcessorService.ts
index 5e660e8081..c2b8884f94 100644
--- a/packages/backend/src/queue/processors/ImportNotesProcessorService.ts
+++ b/packages/backend/src/queue/processors/ImportNotesProcessorService.ts
@@ -192,9 +192,7 @@ export class ImportNotesProcessorService {
 				await fsp.writeFile(destPath, '', 'binary');
 				await this.downloadUrl(file.url, destPath);
 			} catch (e) { // TODO: 何度か再試行
-				if (e instanceof Error || typeof e === 'string') {
-					this.logger.error(e);
-				}
+				this.logger.error('Error importing notes:', e as Error);
 				throw e;
 			}
 
@@ -222,9 +220,7 @@ export class ImportNotesProcessorService {
 				await fsp.writeFile(destPath, '', 'binary');
 				await this.downloadUrl(file.url, destPath);
 			} catch (e) { // TODO: 何度か再試行
-				if (e instanceof Error || typeof e === 'string') {
-					this.logger.error(e);
-				}
+				this.logger.error('Error importing notes:', e as Error);
 				throw e;
 			}
 
@@ -255,9 +251,7 @@ export class ImportNotesProcessorService {
 				await fsp.writeFile(destPath, '', 'binary');
 				await this.downloadUrl(file.url, destPath);
 			} catch (e) { // TODO: 何度か再試行
-				if (e instanceof Error || typeof e === 'string') {
-					this.logger.error(e);
-				}
+				this.logger.error('Error importing notes:', e as Error);
 				throw e;
 			}
 
@@ -313,9 +307,7 @@ export class ImportNotesProcessorService {
 				await fsp.writeFile(path, '', 'utf-8');
 				await this.downloadUrl(file.url, path);
 			} catch (e) { // TODO: 何度か再試行
-				if (e instanceof Error || typeof e === 'string') {
-					this.logger.error(e);
-				}
+				this.logger.error('Error importing notes:', e as Error);
 				throw e;
 			}
 
@@ -365,7 +357,7 @@ export class ImportNotesProcessorService {
 					try {
 						await this.downloadUrl(file.url, filePath);
 					} catch (e) { // TODO: 何度か再試行
-						this.logger.error(e instanceof Error ? e : new Error(e as string));
+						this.logger.error('Error importing notes:', e as Error);
 					}
 					const driveFile = await this.driveService.addFile({
 						user: user,
@@ -504,7 +496,7 @@ export class ImportNotesProcessorService {
 					try {
 						await this.downloadUrl(file.url, filePath);
 					} catch (e) { // TODO: 何度か再試行
-						this.logger.error(e instanceof Error ? e : new Error(e as string));
+						this.logger.error('Error importing notes:', e as Error);
 					}
 					const driveFile = await this.driveService.addFile({
 						user: user,
@@ -628,7 +620,7 @@ export class ImportNotesProcessorService {
 							try {
 								await this.downloadUrl(videos[0].url, filePath);
 							} catch (e) { // TODO: 何度か再試行
-								this.logger.error(e instanceof Error ? e : new Error(e as string));
+								this.logger.error('Error importing notes:', e as Error);
 							}
 							const driveFile = await this.driveService.addFile({
 								user: user,
@@ -653,7 +645,7 @@ export class ImportNotesProcessorService {
 							try {
 								await this.downloadUrl(file.media_url_https, filePath);
 							} catch (e) { // TODO: 何度か再試行
-								this.logger.error(e instanceof Error ? e : new Error(e as string));
+								this.logger.error('Error importing notes:', e as Error);
 							}
 
 							const driveFile = await this.driveService.addFile({
@@ -673,7 +665,7 @@ export class ImportNotesProcessorService {
 			const createdNote = await this.noteCreateService.import(user, { createdAt: date, reply: parentNote, text: text, files: files });
 			if (tweet.childNotes) this.queueService.createImportTweetsToDbJob(user, tweet.childNotes, createdNote.id);
 		} catch (e) {
-			this.logger.warn(`Error: ${e}`);
+			this.logger.error('Error importing notes:', e as Error);
 		}
 	}
 
diff --git a/packages/backend/src/queue/processors/ImportUserListsProcessorService.ts b/packages/backend/src/queue/processors/ImportUserListsProcessorService.ts
index db9255b35d..d30ebfa187 100644
--- a/packages/backend/src/queue/processors/ImportUserListsProcessorService.ts
+++ b/packages/backend/src/queue/processors/ImportUserListsProcessorService.ts
@@ -15,6 +15,7 @@ import { UserListService } from '@/core/UserListService.js';
 import { IdService } from '@/core/IdService.js';
 import { UtilityService } from '@/core/UtilityService.js';
 import { bindThis } from '@/decorators.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type * as Bull from 'bullmq';
 import type { DbUserImportJobData } from '../types.js';
@@ -102,7 +103,7 @@ export class ImportUserListsProcessorService {
 
 				this.userListService.addMember(target, list!, user);
 			} catch (e) {
-				this.logger.warn(`Error in line:${linenum} ${e}`);
+				this.logger.warn(`Error in line:${linenum} ${renderInlineError(e)}`);
 			}
 		}
 
diff --git a/packages/backend/src/queue/processors/ScheduleNotePostProcessorService.ts b/packages/backend/src/queue/processors/ScheduleNotePostProcessorService.ts
index d823d98ef1..d96199c201 100644
--- a/packages/backend/src/queue/processors/ScheduleNotePostProcessorService.ts
+++ b/packages/backend/src/queue/processors/ScheduleNotePostProcessorService.ts
@@ -12,6 +12,7 @@ import { DI } from '@/di-symbols.js';
 import { NotificationService } from '@/core/NotificationService.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
 import type { MiScheduleNoteType } from '@/models/NoteSchedule.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type * as Bull from 'bullmq';
 import type { ScheduleNotePostJobData } from '../types.js';
@@ -129,10 +130,11 @@ export class ScheduleNotePostProcessorService {
 					channel,
 				}).catch(async (err: IdentifiableError) => {
 					this.notificationService.createNotification(me.id, 'scheduledNoteFailed', {
-						reason: err.message,
+						reason: renderInlineError(err),
 					});
 					await this.noteScheduleRepository.remove(data);
-					throw this.logger.error(`Schedule Note Failed Reason: ${err.message}`);
+					this.logger.error(`Scheduled note failed:`, err);
+					throw err;
 				});
 				await this.noteScheduleRepository.remove(data);
 				this.notificationService.createNotification(me.id, 'scheduledNotePosted', {
diff --git a/packages/backend/src/queue/processors/SystemWebhookDeliverProcessorService.ts b/packages/backend/src/queue/processors/SystemWebhookDeliverProcessorService.ts
index f6bef52684..61042ff718 100644
--- a/packages/backend/src/queue/processors/SystemWebhookDeliverProcessorService.ts
+++ b/packages/backend/src/queue/processors/SystemWebhookDeliverProcessorService.ts
@@ -12,6 +12,7 @@ import type Logger from '@/logger.js';
 import { HttpRequestService } from '@/core/HttpRequestService.js';
 import { StatusError } from '@/misc/status-error.js';
 import { bindThis } from '@/decorators.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import { SystemWebhookDeliverJobData } from '../types.js';
 
@@ -63,7 +64,7 @@ export class SystemWebhookDeliverProcessorService {
 
 			return 'Success';
 		} catch (res) {
-			this.logger.error(res as Error);
+			this.logger.error(`Failed to send webhook: ${renderInlineError(res)}`);
 
 			this.systemWebhooksRepository.update({ id: job.data.webhookId }, {
 				latestSentAt: new Date(),
diff --git a/packages/backend/src/server/FileServerService.ts b/packages/backend/src/server/FileServerService.ts
index 4ef5539cff..2e3e8df7ea 100644
--- a/packages/backend/src/server/FileServerService.ts
+++ b/packages/backend/src/server/FileServerService.ts
@@ -32,6 +32,7 @@ import { getIpHash } from '@/misc/get-ip-hash.js';
 import { AuthenticateService } from '@/server/api/AuthenticateService.js';
 import { SkRateLimiterService } from '@/server/SkRateLimiterService.js';
 import { Keyed, RateLimit, sendRateLimitHeaders } from '@/misc/rate-limit-utils.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import type { FastifyInstance, FastifyRequest, FastifyReply, FastifyPluginOptions } from 'fastify';
 
 const _filename = fileURLToPath(import.meta.url);
@@ -120,7 +121,7 @@ export class FileServerService {
 
 	@bindThis
 	private async errorHandler(request: FastifyRequest<{ Params?: { [x: string]: any }; Querystring?: { [x: string]: any }; }>, reply: FastifyReply, err?: any) {
-		this.logger.error(`${err}`);
+		this.logger.error(`Unhandled error in file server: ${renderInlineError(err)}`);
 
 		reply.header('Cache-Control', 'max-age=300');
 
diff --git a/packages/backend/src/server/ServerService.ts b/packages/backend/src/server/ServerService.ts
index 2d20aa1222..77b4519570 100644
--- a/packages/backend/src/server/ServerService.ts
+++ b/packages/backend/src/server/ServerService.ts
@@ -21,6 +21,7 @@ import { genIdenticon } from '@/misc/gen-identicon.js';
 import { UserEntityService } from '@/core/entities/UserEntityService.js';
 import { LoggerService } from '@/core/LoggerService.js';
 import { bindThis } from '@/decorators.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { ActivityPubServerService } from './ActivityPubServerService.js';
 import { NodeinfoServerService } from './NodeinfoServerService.js';
 import { ApiServerService } from './api/ApiServerService.js';
@@ -277,7 +278,7 @@ export class ServerService implements OnApplicationShutdown {
 					this.logger.error(`Port ${this.config.port} is already in use by another process.`);
 					break;
 				default:
-					this.logger.error(err);
+					this.logger.error(`Unhandled error in server: ${renderInlineError(err)}`);
 					break;
 			}
 
diff --git a/packages/backend/src/server/api/ApiCallService.ts b/packages/backend/src/server/api/ApiCallService.ts
index 5c9e5717bb..ce0078cd93 100644
--- a/packages/backend/src/server/api/ApiCallService.ts
+++ b/packages/backend/src/server/api/ApiCallService.ts
@@ -20,6 +20,7 @@ import { RoleService } from '@/core/RoleService.js';
 import type { Config } from '@/config.js';
 import { sendRateLimitHeaders } from '@/misc/rate-limit-utils.js';
 import { SkRateLimiterService } from '@/server/SkRateLimiterService.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { ApiError } from './error.js';
 import { ApiLoggerService } from './ApiLoggerService.js';
 import { AuthenticateService, AuthenticationError } from './AuthenticateService.js';
@@ -100,7 +101,7 @@ export class ApiCallService implements OnApplicationShutdown {
 			throw err;
 		} else {
 			const errId = randomUUID();
-			this.logger.error(`Internal error occurred in ${ep.name}: ${err.message}`, {
+			this.logger.error(`Internal error occurred in ${ep.name}: ${renderInlineError(err)}`, {
 				ep: ep.name,
 				ps: data,
 				e: {
@@ -112,7 +113,7 @@ export class ApiCallService implements OnApplicationShutdown {
 			});
 
 			if (this.config.sentryForBackend) {
-				Sentry.captureMessage(`Internal error occurred in ${ep.name}: ${err.message}`, {
+				Sentry.captureMessage(`Internal error occurred in ${ep.name}: ${renderInlineError(err)}`, {
 					level: 'error',
 					user: {
 						id: userId,
diff --git a/packages/backend/src/server/api/SigninWithPasskeyApiService.ts b/packages/backend/src/server/api/SigninWithPasskeyApiService.ts
index f84f50523b..38886f8876 100644
--- a/packages/backend/src/server/api/SigninWithPasskeyApiService.ts
+++ b/packages/backend/src/server/api/SigninWithPasskeyApiService.ts
@@ -128,7 +128,7 @@ export class SigninWithPasskeyApiService {
 		try {
 			authorizedUserId = await this.webAuthnService.verifySignInWithPasskeyAuthentication(context, credential);
 		} catch (err) {
-			this.logger.warn(`Passkey challenge Verify error! : ${err}`);
+			this.logger.warn('Passkey challenge verify error:', err as Error);
 			const errorId = (err as IdentifiableError).id;
 			return error(403, {
 				id: errorId,
diff --git a/packages/backend/src/server/api/endpoints/drive/files/create.ts b/packages/backend/src/server/api/endpoints/drive/files/create.ts
index 5373cc4dd8..939eadad9b 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/create.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/create.ts
@@ -10,6 +10,8 @@ import { Endpoint } from '@/server/api/endpoint-base.js';
 import { DriveFileEntityService } from '@/core/entities/DriveFileEntityService.js';
 import { DriveService } from '@/core/DriveService.js';
 import type { Config } from '@/config.js';
+import { ApiLoggerService } from '@/server/api/ApiLoggerService.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { ApiError } from '../../../error.js';
 import { MiMeta } from '@/models/_.js';
 import { DI } from '@/di-symbols.js';
@@ -95,6 +97,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 		private driveFileEntityService: DriveFileEntityService,
 		private driveService: DriveService,
+		private readonly apiLoggerService: ApiLoggerService,
 	) {
 		super(meta, paramDef, async (ps, me, _, file, cleanup, ip, headers) => {
 			// Get 'name' parameter
@@ -130,7 +133,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				return await this.driveFileEntityService.pack(driveFile, { self: true });
 			} catch (err) {
 				if (err instanceof Error || typeof err === 'string') {
-					console.error('Error saving drive file:', err);
+					this.apiLoggerService.logger.error(`Error saving drive file: ${renderInlineError(err)}`);
 				}
 				if (err instanceof IdentifiableError) {
 					if (err.id === '282f77bf-5816-4f72-9264-aa14d8261a21') throw new ApiError(meta.errors.inappropriate);
diff --git a/packages/backend/src/server/api/endpoints/i/move.ts b/packages/backend/src/server/api/endpoints/i/move.ts
index 7852b5a2e1..e2a14b61af 100644
--- a/packages/backend/src/server/api/endpoints/i/move.ts
+++ b/packages/backend/src/server/api/endpoints/i/move.ts
@@ -17,7 +17,7 @@ import { ApiLoggerService } from '@/server/api/ApiLoggerService.js';
 import { GetterService } from '@/server/api/GetterService.js';
 import { ApPersonService } from '@/core/activitypub/models/ApPersonService.js';
 import { UserEntityService } from '@/core/entities/UserEntityService.js';
-
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import * as Acct from '@/misc/acct.js';
 import { DI } from '@/di-symbols.js';
 import { MiMeta } from '@/models/_.js';
@@ -105,7 +105,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			const { username, host } = Acct.parse(ps.moveToAccount);
 			// retrieve the destination account
 			let moveTo = await this.remoteUserResolveService.resolveUser(username, host).catch((e) => {
-				this.apiLoggerService.logger.warn(`failed to resolve remote user: ${e}`);
+				this.apiLoggerService.logger.warn(`failed to resolve remote user: ${renderInlineError(e)}`);
 				throw new ApiError(meta.errors.noSuchUser);
 			});
 			const destination = await this.getterService.getUser(moveTo.id) as MiLocalUser | MiRemoteUser;
diff --git a/packages/backend/src/server/api/endpoints/i/update.ts b/packages/backend/src/server/api/endpoints/i/update.ts
index 5a160d632c..193f2e8313 100644
--- a/packages/backend/src/server/api/endpoints/i/update.ts
+++ b/packages/backend/src/server/api/endpoints/i/update.ts
@@ -34,6 +34,7 @@ import { verifyFieldLinks } from '@/misc/verify-field-link.js';
 import { AvatarDecorationService } from '@/core/AvatarDecorationService.js';
 import { notificationRecieveConfig } from '@/models/json-schema/user.js';
 import { userUnsignedFetchOptions } from '@/const.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { ApiLoggerService } from '../../ApiLoggerService.js';
 import { ApiError } from '../../error.js';
 
@@ -516,7 +517,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 					// Retrieve the old account
 					const knownAs = await this.remoteUserResolveService.resolveUser(username, host).catch((e) => {
-						this.apiLoggerService.logger.warn(`failed to resolve dstination user: ${e}`);
+						this.apiLoggerService.logger.warn(`failed to resolve destination user: ${renderInlineError(e)}`);
 						throw new ApiError(meta.errors.noSuchUser);
 					});
 					if (knownAs.id === _user.id) throw new ApiError(meta.errors.forbiddenToSetYourself);
diff --git a/packages/backend/src/server/api/endpoints/users/show.ts b/packages/backend/src/server/api/endpoints/users/show.ts
index 7b1c8adfb8..84eb661742 100644
--- a/packages/backend/src/server/api/endpoints/users/show.ts
+++ b/packages/backend/src/server/api/endpoints/users/show.ts
@@ -13,6 +13,7 @@ import { RemoteUserResolveService } from '@/core/RemoteUserResolveService.js';
 import { DI } from '@/di-symbols.js';
 import PerUserPvChart from '@/core/chart/charts/per-user-pv.js';
 import { RoleService } from '@/core/RoleService.js';
+import { renderInlineError } from '@/misc/render-inline-error.js';
 import { ApiError } from '../../error.js';
 import { ApiLoggerService } from '../../ApiLoggerService.js';
 import type { FindOptionsWhere } from 'typeorm';
@@ -131,7 +132,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				// Lookup user
 				if (typeof ps.host === 'string' && typeof ps.username === 'string') {
 					user = await this.remoteUserResolveService.resolveUser(ps.username, ps.host).catch(err => {
-						this.apiLoggerService.logger.warn(`failed to resolve remote user: ${err}`);
+						this.apiLoggerService.logger.warn(`failed to resolve remote user: ${renderInlineError(err)}`);
 						throw new ApiError(meta.errors.failedToResolveRemoteUser);
 					});
 				} else {