This is probably something very simple that I am missing. I have IIS installed on D drive with standard paths, so I have D:\inetpub\custerr. This has language specific subfolders in it for en-US, de-DE and es-ES. I have a custom 401 page to inform users that are not allowed in what to do to gain access. However, it doesn't matter what I set the language in my browser to I always get the en-US file.
I have changed the IIS error pages to point the 401 request to "d:\inetpub\custerr\<LANGUAGE-TAG>\Z-net-401.htm". I checked the box to tell IIS to try to find language specific subfolders.
The languages in the request are below, the browser is Chrome.
Accept-Language: de-DE,de;q=0.8,es;q=0.6,en-GB;q=0.4,en;q=0.2
I can see this in the failed request trace. I also see the en-US file being accessed:
FileName="d:\inetpub\custerr\en-US\Z-net-401.htm", UserName="", DomainName=""
There is a directory of d:\inetpub\custerr\de-DE that contains a file Z-net-401.htm but it is not served, the en-US one is.
Any suggestions welcome, like "hey, there's a checkbox you need to check to make this work dude".