Hello,
I have just created a simple test for myself and was successfully able to step into my .NET assemble. Here are the steps:
1) Make sure that the project is build in debug mode (as opposed to release).
2) When you specify the module in TestStand, make sure to click on the source code tab also and select all the appropriate files.
3) Put a breakpoint on the TestStand step.
4) During execution, when you are break on that step, select the "step into" debugging option.
This will automatically open up Visual Studio .NET and step into the code that you just called from TestStand. It may take a minute or two before it allows you to debug in Visual Studio. Then you can debug as usual and step out of the assembly when you are done to continue executing in TestStand.
Thank you for contacting National Instruments. I hope you find this information helpful. Take care and good luck!
Regards,
Aaron B.
National Instruments