A LabVIEW user interface I was working with hung recently. I suspected the front panel was locked because I had done something stupid, but I was surprised to find out what it was. I had put an Event Structure in a case structure that wasn’t executing and this had caused the hang.
As I program in LabVIEW I am surprised by the number of times small bits of code cause large problems. For example, I was working with a large system that communicated with many instruments. I made some changes, tried running the code, and the program locked up! My gut reaction was to blame the LabVIEW development environment or a driver, but in the end I discovered the code I changed caused the hang.