When profile is clicked without signing in

[UltiGeek]

this message appears

Fatal error: Uncaught exception 'Exception' with message 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1' in /home/yoteyote/public_html/lib/Db.php:75 Stack trace: #0 /home/yoteyote/public_html/lib/Db.php(89): Db->query('SELECT * FROM ...') #1 /home/yoteyote/public_html/lib/User.php(16): Db->get_row('SELECT * FROM ...') #2 /home/yoteyote/public_html/includes/profile.php(8): User->getUser('*', 'user_id = ') #3 {main} thrown in /home/yoteyote/public_html/lib/Db.php on line 75
#23