Hi,
Is the problem that you are seeing is that the Operator Interface and the Sequence Editor crash completely when running this code? If not, can you give a little bit more detail about what problems you are seeing?
If it is crashing, I would suggest stepping into your code with a breakpoint and identifying which part is causing the problem. Either way, it is highly unusual it is completely closing down on its own just by running this one step.
Best Regards,
Allen P.
National Instruments