Thread:Project:Support desk/Links to non-existent pages don't go to the "missing page" page when SEF is enabled

I have a new wiki that we're using for internal documentation (so unfortunately I can't link to it here) and for some reason the page links don't seem to work on non-existent pages.

I have a bunch of articles such as Server1, Server2 , Server3 and so on.

For pages that exist, these are correctly turned into links to /Server1, /Server2, /Server3 and so on.

For pages that don't exist though, I get links like this: /Main_Page?title=Server1&action=edit&redlink=1

My wiki is installed in the root of the domain/site, and this is my .htaccess:

And part of my LocalSettings:

MediaWiki 1.21.2 PHP 5.4.9 MySQL 5.5.32