Terminated GP task still appearing in UWL

Hello Everyone, I'm having the following problem: A terminated guided procedure process keeps appearing on a user's universal work list.

I've already verified that the process is really terminated. Also, I've tried to delete the process template but I keep getting a Java Null Pointer exception every time I try to run the "Archiving and Deleting" option.

Has anyone faced the same problem trying to delete terminated process templates?

All your help and suggestions are greatly appreciated.