I have an automation software which uses a simple user interface (with WinForms) on .net Framework 4.8. It uses the default tab control, which has 7 tab pages. Around 5 timers, and also 12 separate threads.
I do have 2 customized user controls on the project, but those are not in use.
The system works just fine. After a period of time (it seems to be at random), in the last time I got it (the problem) it was after something about 1 to 2 hours of the system running.
The symptoms:
All the threads are running normally.
All the timers and all the other system events stopped working.
Can't click anything on the screen, nothing responds to interaction (not event the 'X' button to close the window).
There is just one event that is still working: The double click on the systray icon, but the menu attached to it (even though it opens) can't be clicked.
All the controls in the form are "working". They all have their values and everything attached to it. They're just not running. No animation, no nothing. Just a static screen.
And no, the form isn't disabled. It is enabled and visible.
I've tried checking individually all the timers and all the events that could be triggered by the form somehow. Nothing responds (and there isn't a 'Not responding' message on the form window as usual).
Looked into all the possible angles, but no luck so far.