Thread:Project:Support desk/Mediawiki 1.23.9 Internal error when click the "Preferences" link

HI, When a user attempts to click the "Preferences" link he get this error

0 /.../mediawiki-1.23.9/includes/Preferences.php(1232): Preferences::getPreferences(Object(User), Object(RequestContext))
 * 1) 1 /.../mediawiki-1.23.9/includes/specials/SpecialPreferences.php(58): Preferences::getFormObject(Object(User), Object(RequestContext))
 * 2) 2 /.../mediawiki-1.23.9/includes/specialpage/SpecialPage.php(379): SpecialPreferences->execute(NULL)
 * 3) 3 /.../mediawiki-1.23.9/includes/specialpage/SpecialPageFactory.php(503): SpecialPage->run(NULL)
 * 4) 4 /appli/projects/fusionforge/apache_2.2.24/htdocs/fusionforge/mediawiki-1.23.9/includes/Wiki.php(285): SpecialPageFactory::executePath(Object(Title), Object(RequestContext))
 * 5) 5 /.../mediawiki-1.23.9/includes/Wiki.php(588): MediaWiki->performRequest
 * 6) 6 /.../mediawiki-1.23.9/includes/Wiki.php(447): MediaWiki->main
 * 7) 7 /.../mediawiki-1.23.9/index.php(46): MediaWiki->run
 * 8) 8 {main}

our versions are as follows: Mediawiki 1.23.9, php_5.3.23, postgresql 9.3.4

Please help to resolve the above issue.