Debugging ASP.NET Web Request Failures: The Complete Guide

You’re sending an HTTP request to your ASP.NET server, and out of the blue, it returns a 500 error. Now what? The error code doesn’t say too much by itself. Did a database request fail? What was the exact database query? Was there an exception? What kind of exception? On which line of code did it happen? And what were the local variables? Wouldn’t it be great if you could see the failure as if you’re breaking on an exception while debugging in Visual Studio?