Today my xenforo website went down with a 500 Internal error. It turned out to be a corrupt .htaccess file (which has been happening more often). When I went to to look at the server log, this was the last error received before the server went down. Code: [26-Apr-2015 06:06:07 UTC] PHP Fatal error: Call to undefined method XenForo_Link::includeTitlesInUrls() in /home/itsnotch/public_html/vicegamers/forums/library/XenForo/Application.php on line 804 I have no idea if this is what caused it, but I figured here would be a good place to start analyzing the problem to get to the root issue. Has anybody seen this before? I don't know what it relates to and how I could fix it. I have just increased the memory limit in the php.ini file on the server. My server also uses a WP instillation, so I increased the php memory limit in the wp config file as well.