I'm porting some old ASP/.Net applications over to a clean build of w2k8R2 running IIS7. The older .Net applications and some 3rd-party dlls require enabling 32-bit mode for the applications pools they run in. When I do this, error pages (both custom and detailed) disappear.
The correct error status is returned to a browser, but there is no content – just a blank page. This happens regardless of the custom/detailed local/remote Feature Settings for error pages and regardless of whether a local or remote browser is used. No errors are thrown that I can detect, just no content in the pages.
The fact that I can't find any references to this problem anywhere lead to suspect that it's a problem I've introduced earlier in the build. I can't see how, though.
Has anyone experienced anything similar?
Best Answer
I'd not taken my build back far enough. The culprit turned out to be an old GAHelper.dll that I'd ported over from the old configuration. It doesn't seem to play nicely with IIS7. We use it on most of these sites, so I had added it as an ISAPI filter at the top level. Removing it allows errors to display as expected.