diff --git a/packages/server/src/models/TaskStateModel.ts b/packages/server/src/models/TaskStateModel.ts
index 15b3b1de6..e01e88cf8 100644
--- a/packages/server/src/models/TaskStateModel.ts
+++ b/packages/server/src/models/TaskStateModel.ts
@@ -1,4 +1,5 @@
 import { TaskId, TaskState } from '../services/database/types';
+import { ErrorBadRequest, ErrorCode } from '../utils/errors';
 import BaseModel from './BaseModel';
 
 export default class TaskStateModel extends BaseModel<TaskState> {
@@ -32,13 +33,13 @@ export default class TaskStateModel extends BaseModel<TaskState> {
 
 	public async start(taskId: TaskId) {
 		const state = await this.loadByTaskId(taskId);
-		if (state.running) throw new Error(`Task is already running: ${taskId}`);
+		if (state.running) throw new ErrorBadRequest(`Task is already running: ${taskId}`, { code: ErrorCode.TaskAlreadyRunning });
 		await this.save({ id: state.id, running: 1 });
 	}
 
 	public async stop(taskId: TaskId) {
 		const state = await this.loadByTaskId(taskId);
-		if (!state.running) throw new Error(`Task is not running: ${taskId}`);
+		if (!state.running) throw new ErrorBadRequest(`Task is not running: ${taskId}`, { code: ErrorCode.TaskAlreadyRunning });
 		await this.save({ id: state.id, running: 0 });
 	}
 
diff --git a/packages/server/src/services/TaskService.test.ts b/packages/server/src/services/TaskService.test.ts
index 70e5bab37..7c48b26b6 100644
--- a/packages/server/src/services/TaskService.test.ts
+++ b/packages/server/src/services/TaskService.test.ts
@@ -1,5 +1,6 @@
 import config from '../config';
 import { Models } from '../models/factory';
+import { ErrorCode } from '../utils/errors';
 import { afterAllTests, beforeAllDb, beforeEachDb, expectThrow, models } from '../utils/testing/testUtils';
 import { Env } from '../utils/types';
 import { TaskId } from './database/types';
@@ -14,6 +15,23 @@ const newService = () => {
 	});
 };
 
+const createDemoTasks = (): Task[] => {
+	return [
+		{
+			id: TaskId.DeleteExpiredTokens,
+			description: '',
+			run: (_models: Models) => {},
+			schedule: '',
+		},
+		{
+			id: TaskId.CompressOldChanges,
+			description: '',
+			run: (_models: Models) => {},
+			schedule: '',
+		},
+	];
+};
+
 describe('TaskService', () => {
 
 	beforeAll(async () => {
@@ -31,98 +49,66 @@ describe('TaskService', () => {
 	test('should register a task', async () => {
 		const service = newService();
 
-		const task: Task = {
-			id: TaskId.DeleteExpiredTokens,
-			description: '',
-			run: (_models: Models) => {},
-			schedule: '',
-		};
-
-		await service.registerTask(task);
+		const tasks = createDemoTasks();
+		await service.registerTasks(tasks);
 
 		expect(service.tasks[TaskId.DeleteExpiredTokens]).toBeTruthy();
-		await expectThrow(async () => service.registerTask(task));
+		expect(service.tasks[TaskId.CompressOldChanges]).toBeTruthy();
+		await expectThrow(async () => service.registerTask(tasks[0]));
 	});
 
-	// test('should run a task', async function() {
-	// 	const service = newService();
-
-	// 	let taskStarted = false;
-	// 	let waitToFinish = true;
-	// 	let finishTask = false;
-	// 	let taskHasRan = false;
-
-	// 	const taskId = TaskId.DeleteExpiredTokens;
-
-	// 	const task: Task = {
-	// 		id: taskId,
-	// 		description: '',
-	// 		run: async (_models: Models) => {
-	// 			taskStarted = true;
-
-	// 			const iid = setInterval(() => {
-	// 				if (waitToFinish) return;
-
-	// 				if (finishTask) {
-	// 					clearInterval(iid);
-	// 					taskHasRan = true;
-	// 				}
-	// 			}, 1);
-	// 		},
-	// 		schedule: '',
-	// 	};
-
-	// 	await service.registerTask(task);
-
-	// 	expect((await service.taskState(taskId)).running).toBe(0);
-
-	// 	const startTime = new Date();
-
-	// 	void service.runTask(taskId, RunType.Manual);
-	// 	while (!taskStarted) {
-	// 		await msleep(1);
-	// 	}
-
-	// 	expect((await service.taskState(taskId)).running).toBe(1);
-	// 	waitToFinish = false;
-
-	// 	while (!taskHasRan) {
-	// 		await msleep(1);
-	// 		finishTask = true;
-	// 	}
-
-	// 	expect((await service.taskState(taskId)).running).toBe(0);
-
-	// 	const events = await service.taskLastEvents(taskId);
-	// 	expect(events.taskStarted.created_time).toBeGreaterThanOrEqual(startTime.getTime());
-	// 	expect(events.taskCompleted.created_time).toBeGreaterThan(startTime.getTime());
-	// });
-
 	test('should not run if task is disabled', async () => {
 		const service = newService();
 
 		let taskHasRan = false;
 
-		const taskId = TaskId.DeleteExpiredTokens;
-
-		const task: Task = {
-			id: taskId,
-			description: '',
-			run: async (_models: Models) => {
-				taskHasRan = true;
-			},
-			schedule: '',
-		};
-
-		await service.registerTask(task);
+		const tasks = createDemoTasks();
+		tasks[0].run = async (_models: Models) => {
+			taskHasRan = true;
+		},
+		await service.registerTasks(tasks);
+		const taskId = tasks[0].id;
 
 		await service.runTask(taskId, RunType.Manual);
 		expect(taskHasRan).toBe(true);
 
 		taskHasRan = false;
-		await models().taskState().disable(task.id);
+		await models().taskState().disable(taskId);
 		await service.runTask(taskId, RunType.Manual);
 		expect(taskHasRan).toBe(false);
 	});
 
+	test('should not run if task is already running', async () => {
+		const service = newService();
+
+		const tasks = createDemoTasks();
+		await service.registerTasks(tasks);
+		const task = tasks[0];
+
+		const state = await models().taskState().loadByTaskId(task.id);
+		await models().taskState().save({ id: state.id, running: 1 });
+
+		await expectThrow(async () => service.runTask(task.id, RunType.Manual), ErrorCode.TaskAlreadyRunning);
+	});
+
+	test('should reset interrupted tasks', async () => {
+		const service = newService();
+
+		const tasks = createDemoTasks();
+		await service.registerTasks(tasks);
+		const task = tasks[0];
+
+		const state = await models().taskState().loadByTaskId(task.id);
+		await models().taskState().save({ id: state.id, running: 1 });
+
+		const stateBefore = await models().taskState().loadByTaskId(task.id);
+
+		await service.resetInterruptedTasks();
+
+		const stateAfter = await models().taskState().loadByTaskId(task.id);
+
+		expect(stateBefore.running).toBe(1);
+		expect(stateAfter.running).toBe(0);
+	});
+
 });
diff --git a/packages/server/src/services/TaskService.ts b/packages/server/src/services/TaskService.ts
index 69216ab0f..34a9985c6 100644
--- a/packages/server/src/services/TaskService.ts
+++ b/packages/server/src/services/TaskService.ts
@@ -5,7 +5,7 @@ import BaseService from './BaseService';
 import { Event, EventType, TaskId, TaskState } from './database/types';
 import { Services } from './types';
 import { _ } from '@joplin/lib/locale';
-import { ErrorNotFound } from '../utils/errors';
+import { ErrorCode, ErrorNotFound } from '../utils/errors';
 import { durationToMilliseconds } from '../utils/time';
 
 const cron = require('node-cron');
@@ -104,6 +104,16 @@ export default class TaskService extends BaseService {
 		};
 	}
 
+	public async resetInterruptedTasks() {
+		const taskStates = await this.models.taskState().all();
+		for (const taskState of taskStates) {
+			if (taskState.running) {
+				logger.warn(`Found a task that was in running state: ${this.taskDisplayString(taskState.task_id)} - resetting it.`);
+				await this.models.taskState().stop(taskState.task_id);
+			}
+		}
+	}
+
 	private taskById(id: TaskId): Task {
 		if (!this.tasks_[id]) throw new Error(`No such task: ${id}`);
 		return this.tasks_[id];
@@ -159,13 +169,28 @@ export default class TaskService extends BaseService {
 				interval = null;
 			}
 
+			const runTaskWithErrorChecking = async (taskId: TaskId) => {
+				try {
+					await this.runTask(taskId, RunType.Scheduled);
+				} catch (error) {
+					if (error.code === ErrorCode.TaskAlreadyRunning) {
+						// This is not critical but we should log a warning
+						// because it may mean that the interval is too tight,
+						// or the task is taking too long.
+						logger.warn(`Tried to start ${this.taskDisplayString(taskId)} but it was already running`);
+					} else {
+						logger.error(`Failed running task ${this.taskDisplayString(taskId)}`, error);
+					}
+				}
+			};
+
 			if (interval !== null) {
 				setInterval(async () => {
-					await this.runTask(Number(taskId), RunType.Scheduled);
+					await runTaskWithErrorChecking(Number(taskId));
 				}, interval);
 			} else {
 				cron.schedule(task.schedule, async () => {
-					await this.runTask(Number(taskId), RunType.Scheduled);
+					await runTaskWithErrorChecking(Number(taskId));
 				});
 			}
 		}
diff --git a/packages/server/src/utils/errors.ts b/packages/server/src/utils/errors.ts
index ec339fb5a..9f41e32e4 100644
--- a/packages/server/src/utils/errors.ts
+++ b/packages/server/src/utils/errors.ts
@@ -6,6 +6,7 @@ export enum ErrorCode {
 	NoSub = 'no_sub',
 	NoStripeSub = 'no_stripe_sub',
 	InvalidOrigin = 'invalidOrigin',
+	TaskAlreadyRunning = 'taskAlreadyRunning',
 }
 
 export interface ErrorOptions {
diff --git a/packages/server/src/utils/setupTaskService.ts b/packages/server/src/utils/setupTaskService.ts
index ee6360c44..d8864b359 100644
--- a/packages/server/src/utils/setupTaskService.ts
+++ b/packages/server/src/utils/setupTaskService.ts
@@ -104,5 +104,7 @@ export default async function(env: Env, models: Models, config: Config, services
 
 	await taskService.registerTasks(tasks);
 
+	await taskService.resetInterruptedTasks();
+
 	return taskService;
 }