flowable/flowable-engine · error · FlowableObjectNotFoundException

Cannot find task with id

Error message

Cannot find task with id 

What it means

After the null check, NeedsActiveTaskCmd.execute() looks up the task via the task service. If no task exists with the given id it throws FlowableObjectNotFoundException 'Cannot find task with id <taskId>' with Task.class as the type, indicating the referenced task entity does not exist (or is not visible) in the persistent store.

Source

Thrown at modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/cmd/NeedsActiveTaskCmd.java:53

    protected String taskId;

    public NeedsActiveTaskCmd(String taskId) {
        this.taskId = taskId;
    }

    @Override
    public T execute(CommandContext commandContext) {

        if (taskId == null) {
            throw new FlowableIllegalArgumentException("taskId is null");
        }

        CmmnEngineConfiguration cmmnEngineConfiguration = CommandContextUtil.getCmmnEngineConfiguration(commandContext);
        TaskEntity task = cmmnEngineConfiguration.getTaskServiceConfiguration().getTaskService().getTask(taskId);

        if (task == null) {
            throw new FlowableObjectNotFoundException("Cannot find task with id " + taskId, Task.class);
        }

        if (task.isSuspended()) {
            throw new FlowableException(getSuspendedTaskExceptionPrefix() + " a suspended " + task);
        }

        return execute(commandContext, task);
    }

    /**
     * Subclasses must implement in this method their normal command logic. The provided task is ensured to be active.
     */
    protected abstract T execute(CommandContext commandContext, TaskEntity task);

    /**
     * Subclasses can override this method to provide a customized exception message that will be thrown when the task is suspended.
     */
    protected String getSuspendedTaskExceptionPrefix() {

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Verify the task exists first: taskService.createTaskQuery().taskId(id).singleResult() != null
2. Use freshly fetched task ids from taskService.createTaskQuery() results instead of cached values
3. Catch FlowableObjectNotFoundException to handle missing tasks gracefully

Example fix

// before
taskService.complete(oldTaskId); // task already deleted
// after
Task task = taskService.createTaskQuery().taskId(taskId).singleResult();
if (task != null) { taskService.complete(task.getId()); }

Task t = taskService.createTaskQuery().taskId(taskId).singleResult();
if (t == null) throw new IllegalArgumentException("No such task: " + taskId);

try { taskService.complete(taskId); } catch (FlowableObjectNotFoundException e) { log.warn("Task {} no longer exists", taskId); }

When it happens

Trigger: Executing a task command with an id that was never persisted, was deleted (e.g. cascading delete after case instance termination), or belongs to a different database/tenant scope.

Common situations: Stale task ids cached from a previous run; task deleted by another user/process concurrently; id copied from the BPMN engine (process tasks) while operating on the CMMN engine; test/prod data mixing.

Understand the failure class

Background: Record Not Found Errors: "not found", RecordNotFound, and "was not found" — what they mean and how to fix them — this error's family across 28 libraries.

Related errors

• task ${taskId} doesn't exist
• task ${taskId} doesn't exist
• task ${taskId} doesn't exist
• No External Worker job found for id: ${externalJobId}
• taskId is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/aa553995f9843fb3. Report an issue: GitHub.