I used the 'import permissions' or whatever feature (via manage user, it was a link below their name). Now when I log into the ACP, there's nothing there except the 'welcome to phpbb' with the forum statistics and the debug extra warning.
No tabs, no links, nothing. lol, am I missing something or should I dump tables and reinstall?
Edit: If this is a bug and it hasn't been reported, someone do it for me. I don't know how.