Visual Studio 2012/C# breaks code execution, no breakpoint set

Question

I'm having a problem in Visual Studio 2012/C# which is driving me crazy. I have a particular line of code in a C# file with NO breakpoint set. Every time this line should be executed the debugger interrupts the execution of my code like a breakpoint was set. The only difference i noticed is the arrow on the left hand side, indicating the current step. Usually this arrow is yellow (when a breakpoint is set). In my case it is grey.

I have been searching for a solution but did not find anything useful to this. I tried deleting all breakpoints, build project, rebuild project, clean project and it still appears.

Does anyone have the same problems and found a solution this?

normal arrow:

arrow in my case:

Answer 1

This line of code is currently executing, it calls something else, e.g. native code or .NET internal code and an exception happens there. You can see both arrows in the call stack window:

Perhaps you need to turn on "Show external code".

If you can't see the exception dialog, usually you can show it like this: