Thread:Project:Support desk/LoginUser error in 1.18.3/reply (3)

This error message does not look like it comes from MediaWiki. I think it comes from the webserver itself and MediaWiki is not invoked at all. Maybe something with your rewrite rules, but if you have not changed them, they should not break. Or a caching issue. But this might show you old content, but not this error message. I am clueless...