When debugging ASP.NET MVC app, breakpoints are not hit

I had the same problem. Check here: Tools->Options->Debugging

Fix by selecting Enable .Net Framework source stepping

Ok so after 4 hours wasted, I find that setting my web project as the startup project solves the issue! This surely must be a bug...

I hope I save someone out there half a day :)

Some team member deleted the Debug configuration for one project (The MVC Project). Though the Solution configuration was set to "Debug / AnyCPU", if you looked in the configuration for that, the Project-Configuration for the MVC Project was set to Release, with no option for Debug, and all other projects were set as Debug appropriately.

So I added Debug back to the project configurations (Just drop-down "Add"... uncheck the box to add to solution). And viola...

Few more possibilities:

• If you have a client and server in your solution (lets say a WPF and WCF app) you should make sure you select 'multiple startup projects'. [this one is similar to your accepted answer, but useful if you need a client running too]

• Release mode is selected for the project. When doing a fresh get (as I discovered today) on a new machine VS seems to like to switch to 'Release' configuration profile.