I don't have 2020 so I can't look at your code but I can tell you that most of the time when LabVIEW crashes suddenly like you describe it's because of external code (DLLs, ActiveX, USB drivers, etc.) and I see that you're including 3 DLLs in your post so there's a good chance that's it.
If you add some code to do some logging immediately before and after all of your DLL calls, then you should be able to figure out which DLL call is causing it.
Once you figure out which DLL call it is (assuming it is one), then you can investigate more. Some DLL calls might require certain inputs to work while others cause crashes, others might be out of date and don't work on your OS, or the DLL might have missing dependencies.
