I also had the same issue as Josy and followed the link instructions in the link above.
I managed to resolve the issue by modifying the open.inc.php file in /includes/client directory.
Find:
$services= db_query('SELECT topic_id,topic FROM '.TOPIC_TABLE.' WHERE isactive=1 AND dept_id = '.$info.' ORDER BY topic');
Replace With:
$services= db_query('SELECT topic_id,topic FROM '.TOPIC_TABLE.' WHERE isactive=1 ORDER BY topic');
I was comparing some of the differences to a previous mod posted here: (http://www.osticket.com/forums/showthread.php?t=2023&highlight=department+topic). Everything is working as it should with no DB errors.
I also made a slight change to the findtopic.php file.
From:
<option value="">Select Help Topic*lt;/option>
To:
<option value="">Select Help Topic</option>
Hope this helps anyone else who runs into this issue.
-Daren