Re: Cannot modify header information
Database error: []
SELECT * FROM bb_online WHERE user_id = LIMIT 1
Caller: online_logout
The user_id is empty in this case which causes the error.
The question is why it’s empty.
This could be a cookie problem, this could be an alpha bug.
If you have no plugins running and switching to the default template does not make the error go away, it’s a bug and should be reported on TRAC (along with your configuration if possible, server type, PHP, etc)