Unable to edit User names, group.etc in Admin CP

[Koisnake]

After the update, I was unable to edit a user's name, group (which is major since we want to demod and mod new members), MYBB Plaza Turbo money.etc Every time I try to, I get this:
   

The founder of the site forgot to uninstall some programs before upgrading the forums, therefore we are getting these problems. We were able to solve a problem relieving not being able to edit posts thank to you guys.

Any help will be GREATLY appreciated. I've been trying to solve this problem for weeks with no prevail.

[- G33K -]

http://community.mybb.com/thread-75028.html

- Make sure you uploaded all the new files, its easy to forget the admin folder if you had it renamed. Run the file verification under Admincp >> Tools & Maintenance to make sure all files are good.
- If you have plugins that were not deactivated make sure they are compatible with 1.6, re-install them.

[Koisnake]

Thank you so much, I'm going to see if this works!