Visual Studio breakpoints not being hit

Question

I'm working with an ASP.NET MVC project that seems to be having some issues when attaching to the IIS process (w3wp.exe). I'm running the solution and IIS 8.5 on my own local machine so I wouldn't think that this has anything to do with our network. What's strange to me is that I'm able to hit the breakpoints on any other solution I debug locally.

The issue I'm having exactly is that the breakpoints turn to red, hollow circles and never get hit. Usually the fix for this is a Clean/Rebuild of the solution but this hasn't worked. I've confirmed the code is being updated by adding "throw new Exception" to a page and ensuring it shows the exception. Again, this problem is only happening with this one solution. Any other solution I run the debugger with works fine. I've also tried restarting the app pool, the website, IIS, and also my computer.

A few of the articles I read mentioned that anti-virus programs can block a remote debugger from accessing the process. However, the entire setup is contained on my local machine so it doesn't sound like that would be the issue. It does concern me a bit though because we recently hired a new IT guy that's been making a lot of changes to everyone's machine.

One other point to add that's unique about this web application is the binding in IIS. The binding is "*" in order to leverage some custom functionality related to subdomains.

In the meantime, I'll continue to look for a solution but if anybody has any ideas what may be causing this one solution to not debug properly I'd really appreciate it.

EDIT: Found a solution that suggested deleting the ASP.NET temporary files. No luck.

Answer 1

You can't hit breakpoints while attached to IIS process if you haven't logged into your Microsoft account in VS2017.

Answer 2

One of my projects in my solution was set to Release mode. I changed it back to Debug mode, and the breakpoints are hitting now.

Answer 3

In my case the actual process was different from the original started process.

Usually we bind the local-hosted services through the w3wp.exe process. In my case a custom process was used. Changing to that solved the problem.

One more thing, change from Release to Debug mode. In release mode PDB files are not getting updated with breakpoints details. So make sure you are debugging your application in Debug mode.