Visual Studio - suddenly cannot debug tests

I encountered this today. I tried closing the solution but it didn't work. My mistake I set my solution to Release Mode instead of Debug Mode. I set it to Debug then it worked as expected.

I'm using VS 2015 professional.

I was getting the same output after upgrading a test project from VS 2010 to VS 2012 Ultimate Update 3. The message was displayed in Test Output window after using MSTest command to Debug Selected Tests.

I tried to debug tests using Resharper 8 Unit Test Session window. The message in the result window was "Test wasn't run".

The solution that helped me was to modify the test project settings to enable native code debugging as instructed at this link: Uncaught exception thrown by method called through reflection

In case the link does not work:

1. Go to the project right click and select properties.
2. Select 'Debug' tab on the left.
3. Go to ‘Enable Debuggers’ on the bottom
4. Check ‘Enable Native code debugging’ (or 'Enable unmanaged code debugging', depends on version) check box

Thanks to GalDude33 for posting the solution.

Have regularly the same issue with Visual Studio 2012.

Solution : close the current solution and reopen it.

In my case closing and reopening VS was not necessary.