Can you elaborate on what you mean by "LabVIEW did not like that?" If you are seeing an error, can you share the error number or a screenshot.
Additionally, do you know how to highlight execution? I'd suggest walking your task step by step and trying to identify where it stops behaving as expected.
http://www.ni.com/getting-started/labview-basics/debug#Block Diagram Toolbar
Additionally, how do you plan to stop the while loop? It looks like the stop button is only wired up to error statuses
