"The debugger cannot continue running the process."

Question

I've been messing with VS 2010 debugging settings, trying to get stepping into the .NET Framework working. Well, I can't get it to work. I've also tried the Reflector VS plugin and that was working at one point.

Then I randomly started getting this error:

This only happens when I have a breakpoint on a line that calls IEnumerable<T>.ToList(). If I try to step-over or step-into on that line where my breakpoint is set, I get this error dialog and my debugging session ends.

If I move the breakpoint to the line below, the debugger makes it past the ToList() call!

I've tried the following to no avail:

• Removing the Reflector plugin.
• Undoing my changes in the Tools > Options > Debugging window (unchecked the option to step into the .NET Framework; unchecked the source server option; checked the just my code option).
• Unchecked Microsoft Source Server in the Tools > Options > Debugging > Symbols window.
• Cleared the symbol cache.

What is going on?

Answer 1

Because this was the first place I came to when I searched for an answer, I'll add what I found out.

In my case, I had the debugger set up in the solution to start multiple projects. For some reason this setting was changed by Visual Studio so that no project was starting. Correcting the setting in the solution immediately solved the problem.

The problem was not difficult to solve, but the error message was more than a bit irritating.