It's not uncommon to accidentally leave a process hanging and to have a really hard time tracking it down. Different folks seem to have made different "kill all VI" tools, but this should be a native LabVIEW feature supported by NI. The tool should just work. "Ctrl+." doesn't always work. You should be able to push some shortcut that works even if you have a frozen modal dialog or whatever, and all running VIs are stopped, and log of which ones were stopped prints to the screen.