What is debugattach.aspx and why can't the server find it?

Question

I\'m developing on an XP (SP3) machine with VS 2010 and IIS 5.

I have two versions of the same site. We\'ve released our first production version, so I forked the c

Answer 1

I just ran into this as well. I had turned off the Allow unlisted file name extensions setting under Request Filtering on my local IIS server (in order to match our security hardened settings in other environments). Turns out .aspx was being blocked. I turned the setting back on and could attach with the debugger. So I turned it back off, and added an allowance at the site level for .aspx and I can attach with the debugger once again.

I'm curious as well why the debugger is looking for debugattach.aspx, and failing with this error. Especially since my app is MVC and I don't need to serve .aspx.