What causes "The following tasks were not found${tag ? ` in tag '${tag}'` : ''}: ${invalidTasks.join(', ')}" in eyaltoledano/claude-task-master?

List current tasks (get_tasks / task-master list) and retry remove_task with only ids that exist under the active tag

INVALID_TASK_ID

INVALID_TASK_ID

Error message

The following tasks were not found${tag ? ` in tag '${tag}'` : ''}: ${invalidTasks.join(', ')}

What it means

removeTaskDirect pre-validates that every requested id exists in the tasks file for the active tag. If any ids do not resolve to real tasks, it aborts atomically with INVALID_TASK_ID listing all missing ids rather than partially deleting.

Source

Thrown at mcp-server/src/core/direct-functions/remove-task.js:84

		if (!data || !data.tasks) {
			return {
				success: false,
				error: {
					code: 'INVALID_TASKS_FILE',
					message: `No valid tasks found in ${tasksJsonPath}${tag ? ` for tag '${tag}'` : ''}`
				}
			};
		}

		const invalidTasks = taskIdArray.filter(
			(taskId) => !taskExists(data.tasks, taskId)
		);

		if (invalidTasks.length > 0) {
			return {
				success: false,
				error: {
					code: 'INVALID_TASK_ID',
					message: `The following tasks were not found${tag ? ` in tag '${tag}'` : ''}: ${invalidTasks.join(', ')}`
				}
			};
		}

		// Enable silent mode to prevent console logs from interfering with JSON response
		enableSilentMode();

		try {
			// Call removeTask with proper context including tag
			const result = await removeTask(tasksJsonPath, id, {
				projectRoot,
				tag
			});

			if (!result.success) {
				return {
					success: false,

View on GitHub (pinned to c0c98d367c)

Solutions

List current tasks (get_tasks / task-master list) and retry remove_task with only ids that exist under the active tag
Switch to the correct tag argument if the tasks live in another tag
Remove the invalid ids from the comma-separated list and keep only valid ones
If the task was already removed, treat this as success and skip the duplicate call

Example fix

// before
await client.callTool('remove_task', { id: '5,12' }); // 12 no longer exists

// after
await client.callTool('remove_task', { id: '5', projectRoot: '/path/to/project' });

Defensive patterns

Strategy: validation

Validate before calling

const existing = new Set(tasks.map(t => String(t.id)));
const invalid = ids.filter(i => !existing.has(String(i)));
if (invalid.length > 0) throw new Error(`Unknown task ids: ${invalid.join(', ')}`);

Type guard

function allIdsExist(ids, tasks) {
  const known = new Set(tasks.map(t => String(t.id)));
  return Array.isArray(ids) && ids.length > 0 && ids.every(i => known.has(String(i)));
}

Try / catch

try {
  const res = await client.callTool('remove_task', { id: ids.join(','), projectRoot });
  if (res.error?.code === 'INVALID_TASK_ID') {
    const missing = res.error.message.split(':')[1]?.trim();
    console.error(`Re-fetch task list; these ids do not exist in the active tag: ${missing}`);
  }
} catch (e) {
  console.error('remove_task failed:', e.message);
}

Prevention

Refresh the task list right before removing instead of using cached ids
Verify the active tag matches where the target tasks actually live
Treat a 'not found' result on removal as possibly 'already removed' and skip retries
Copy ids directly from list output rather than retyping them

When it happens

Trigger: Calling remove_task with ids that are absent from tasks.json: already-deleted ids, out-of-range numeric ids, typos, comma-separated lists where one id is stale, or ids that exist only in a different tag than the one selected.

Common situations: An agent cached old task ids that were renumbered after updates; user removed tasks in the CLI then repeats the call in MCP; cross-tag confusion (id 3 exists in tag 'backlog' but active tag is 'master'); fat-fingered id like '99' in a 20-task project.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

AI-assisted analysis of eyaltoledano/claude-task-master@c0c98d367c (2026-08-29). Data as JSON: /api/errors/342bf95cff7f090b. Report an issue: GitHub.