Symptoms

Go to PPA Provider Panel > Tasks > Periodic > Scheduled Tasks. Task 'Cleanup canceled tasks' was failed with the following error:

    Task 'Cleanup canceled tasks' (id=2) execution failed.
     Foreign key 'tm_blocker_tasks_fk1' violation while executing ' DELETE FROM tm_tasks WHERE status =  ? AND next_start <  ?'.    

Cause

Inconsistency in the PPA database.

Resolution

Database should be fixed manually.

Since the issue requires complex manipulations with the PPA database, it is recommended to contact Parallels Technical Support for assistance.