MyBB Community Forums

I have a domain with the structure

mydomain.com/ = Wordpress Blog
mydomain.com/forum/ = MyBB

If I try to delete a thread subscription in the user control center, than surprisly comes a page of my Wordpress Blog and the subscription stays ...

This is the link:

usercp2.php?action=removesubscription&type=forum&fid=2&my_post_key=

Any idea? (It is the latest MyBB with the tehme BosstBB)

Thank you!

'usercp2' is dropped days back. Which version of MyBB you are using?
.... or, may be your theme is not updated.