Remove data of instances no longer in archive database not working

1

Hello,

As usually, after encountering an error during tests, I have tried to Remove data of instances no longer in archive database option. Unfortunatelly, it is not working. Blue bar is sliding from left to right for about 10 minutes now. In Designer Studio, I can't remove the steps associated with the corrupted task, and the task also can't be removed because it doesn't load.
Is there any tip, how to remove that?

Best regards