If you get a Referential Integrity constraint violation is that you probably are referencing an user that is not created in the human task server. If you add the Administrator user that's fine, but what about the "mina" user? that's not needed at all. I'm not sure to understand where and how are you creating multiple instances of the human task server.
Can you elaborate more on your problem?
I have resolved this issue.
Thanks for your help!
great.. can you mark this question as answered?