Thread:Project:Support desk/Fatal error after upgrading to 1.19.2/reply (4)

Are you using a modified skin? Try setting $wgDefaultSkin = "vector". Also try disabling all other extensions.

It maybe better to get a fresh, up-to-date LocalSettings.php by rerunning the web installer. Just rename your old LocalSettings file and go to the wiki URL - it will direct you to the installer. When prompted, point it to your old database - the next step will inform you that an existing wiki has been detected and will perform accordingly. Complete the steps to download the new settings file.

Also backup and all that stuff. I won't be responsible for nuking your DB.