Why am I unable to Debug my ASP.NET website in Visual Studio?

Question

I used to be able to attach to my w3wp process and Debug my web application, but this is not working anymore. I have no idea what changed to break this. I\'m using Visual St

Answer 1

In my case I had a Console Application the hosted web page in .Net Framework 4.6.1. When I added a Debug to Conditional compilation symbols, it started to work:

Answer 2

I have had this problem for a while and found my solution on the MS forum (link below). Debug Diagnostic Tool was the culprit for me, but I did not have to uninstall it. I had a crash rule set up for the w3wp process and I simply removed that rule and restarted everything.

Microsoft Forum for Unable to attach error