Need help

Suddenly my site,, give an error when users (other than Admin) try to access the Forums…
“PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 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 ‘WHERE (f.tid = ‘115’)’ at line 2: SELECT COUNT(*) AS expression FROM {forum_index} f INNER JOIN {node} n ON n.nid = .nid WHERE (f.tid = :db_condition_placeholder_0) ; Array ( [:db_condition_placeholder_0] => 115 ) in PagerDefault->execute() (line 74 of /home/jcrogers/public_html/includes/”

I’ve resinstalled minor updates and suspect module updates, restored the site to April 1 version, checked permissions, etc but all to no avail.

Can anyone give me an idea as to the approximate cost to fix this problem? Thanks …

Drupal version: