@Mlipka, Opera GX does not launch either. Other browsers, including Chrome and Firefox, work fine. I have to try the other things and see if they will help.

@Mlipka Whenever I want to start both Opera and Opera Air, the window only pops up for a second, then it closes again. There is no error message. I can do the installation process normally, but when it is time to hit ready or start surfing or so, then the window again just pops up for a second. The pop-up is completely white. The time is too short to take a screenshot, sorry.

I tried restarting my PC, deleted and reinstalled the browser, and checked the Task Manager to see if it indicated any issues, but there seems to be no problem from that side. What can I do to get the browser working again?