So you just moved your application to an IIS7 server, and now you are getting an error when you make a request to it. This seems to be a popular theme on IIS.NET forums these days, and after answering a hundred or so of these posts, I figured I should do something to help people track down and fix their issues with a little less frustration.
Server software, and web servers specifically, are very complex and highly configurable systems that support multi-tier applications using a variety of technologies and subsystems, and endure further complexity due to security, performance, and reliability demands, so it’s a wonder it all works as well as it does in the end. IIS7 strives to improve the experience of diagnosing and solving problems when they do occur, so knowing how to use the new IIS7 diagnostics features can come a long way in helping you become a pro at troubleshooting server problems.
First things first - what’s the problem?
I often find myself asking this question on the forums when someone posts something like “Help, I moved to IIS7 and now my application doesn’t work!