Debug reveals the following error:
SELECT * FROM xoops_session WHERE login_type='1' AND uid>0
Error number: 1054
Error message: Unknown column 'uid' in 'where clause'
change the SQL statement from this
SELECT * FROM xoops_session WHERE login_type='1' AND uid>0
to this
SELECT * FROM xoops_session WHERE login_type='1' AND member_id>0
see if that helps.
I'm not exactly sure what file the code is from. You may need to alter code that is trying to grab info from that statement.