IIS Reverse Proxy Failing on .svc pages and some other pages, works fine for plain html

Question

Software situation: I have a public facing IIS site which needs to communicate to another site through a reverse proxy server. The other site is a SOAP API, with a couple of pages that assist in configuration of it.

I'm using IIS URL Rewrite, and it is working fine for plain html pages, but it fails on come other pages.

Some pages fail with

HTTP Error 404.8 - Not Found
The request filtering module is configured to deny a path in the URL that contains a     hiddenSegment section.

Others fail with simple 404.

If I go to the URL directly from the proxy server it all works fine.

Currently I am proxying from localhost:8080 to [remote ip].

My inbound rule is: (.*) and rewrites to

'http://[remoteip]/{R:1}'

Outbound rule is: pattern (.*), match content within A, Form, Img. Action, rewrite {R:1}

What do I need to do to get the SOAP API working over remote proxy using IIS?

Answer 1

This was solved by removing managed code in the application pool. Change the .NET framework version for the application pool for the remote proxy site to 'no managed code'

It's obvious in hindsight!