Why would the debugger not be stopping at a breakpoint in my ASP.NET application?

Question

I\'m trying to debug a large ASP.NET application.

I set a breakpoint on the first line in Page_Load in Default.aspx.cs.

When I start the application, my

Answer 1

This drove me nuts for a week until I finally noticed a missing setting. This builds on Jay Riggs's answer, but for Visual Studios 2010 instead of 2005. In project properties -> Web -> Debuggers, make sure that the ASP.NET debugger is checked.