Thread:Project:Support desk/Fatal error: Call to a member function addWikiMsg() on a non-object in /home/username/public html/wiki/includes/specials/SpecialLinkSearch.php on line 82/reply (25)

You don't need to turn on any further debugging to fix that error. If you have SSH (shell) access, connect to the server and use a text editor (such as nano or vim) to edit the file includes/specials/SpecialLinkSearch.php. Find line 82, which looks like this: $out->addWikiMsg( ... and change the $out to $wgOut and that fixes the error.

If you don't have SSH access, use FTP or something to access the server, copy the file into your local computer and make the modification with your favorite non-Microsoft Notepad text editor.

It's a nasty bug that slipped into the 1.18.0 release, and I believe this bug has been fixed in 1.18.1 (although I haven't tested 1.18.1 myself). Sadly this means that every unpatched MediaWiki 1.18.0 will have a broken Special:LinkSearch. :-(