Thread:Project talk:Support desk/"MediaWiki:Vector.css" - Broken!/reply

Might be related to your memcached installation. Are you using memcached? If so, what version and how is it configured. Perhaps try turning disabling that temporarily by disabling the configuration for it in your LocalSettings file.

Possibly related incidents:
 * https://bugzilla.wikimedia.org/show_bug.cgi?id=44499
 * https://bugzilla.wikimedia.org/show_bug.cgi?id=52781
 * https://wikitech.wikimedia.org/wiki/Nova_Resource:Wikidata-dev/SAL#January_2