I'm using it on windows 11. It was working fine, and then it just stopped working. When I click on the icon, I see when it logs in automatically with my credentials, and then I see just a blank window (in black) of chitubox. Then a message pops up saying it's not responding. I tried restarting and reinstalling the software. It did not help. I'm still experiencing the same problem.
Before it stopped working had you added any 3rd party keyboard or screen utilities or the like? The QT development platform at the core of Chitubox does not seem to play well with Win 11 add-on stuff...