I encountered a strange problem: when I run a while loop inside an event structure, the front panel freezes. I have been using similar structure many times, and they all worked fine. So I stripped the program down to bare minimum, and it still doesn't work. But when I stripped down a previously working program, it still works. I cannot figure out what might have happened. I run them on the same computer, same version of LabVIEW (I tried both 2013 SP1 and 2016, and got the same results).
Attached are 2 virtually identical simple test programs. After they are executed, the "Big loop" counter will start running. Then when you press "Run", the program starts the waiting loop until the "SET" is pressed. In the working program, the panel is working while waiting for the "SET" button to be pressed (for example, you can still change the A and B values. In the other program, the panel freezes, you cannot change A and B values, but the wait counter is running.
Any idea why such strange phenomenon happened? Thank you very much!