With Commit "0653fd0d" for T258877: MediaWiki sets invalid Content-Encoding: none now the "Content-Encoding" Header was set to "identity". As RFC2616 states, the "identity" value should not be set for "Content-Encoding". Unfortunately this change breaks the URL-Rewrite Module on Microsoft IIS. Outbound-Rules can no longer be apllied to responses with "Content-Encoding: identity".

May you can find a different solution for that problem. For so long we reverted the commit in our environment.

Thanks for listening.

Michael