I am using AAR to reverse proxy requests to a Confluence install. This works fine when the URL contains no spaces. As soon as a space is added to the URL the request returns a 404, the 404 seems to originate from IIS not the Confluence instance.
I have enable Failed Request Tracing as detailed here: http://learn.iis.net/page.aspx/488/using-failed-request-tracing-rules-to-troubleshoot-application-request-routing-arr/
On requests that return the 404 the AAR module does not seem to kick in, there is no information about it in the logs. I have tested this against pages that return 200 and I can see the rewrite works correctly.
Why is AAR not processing URLs with spaces in them? My Reverse Proxy rule matches on everything:
(.*)
And I have no conditions applied to the rule.