Hi , it seems the problem comes from function checkUser(user) of pt.js
It seems unable to handle special characters correctly.
Because of this issue , I still cannot upgrade my community from UBBT 6.5 to 7.1

I think you should release a non-ajax version ASAP.
Thank you very much.

English is not my native language. I try my best to express my thought precisely. I hope you understand what I mean. If any misunderstanding results from culture gaps, I apologize first.