I have error like this the the first page of course and Also in the administrator page.
Unknown column 'visible' in 'where clause'
* FROM mdl_event WHERE timestart + timeduration >= 1093980600 AND
timestart <= 1096572599 AND ( userid = 1 AND courseid = 0 AND
groupid = 0 OR groupid = 0 AND courseid IN (4,1) AND visible = 1)
Also I have Database Administrator in the moodle.