Opera Browser blocks keyboard shortcuts (e.g. Ctrl+Shift+End) in MuseScore for Windows 10
This is not, as I first assumed, a MuseScore or Windows 10 bug, but is caused by the current Opera version. If Opera is running at the same time as MuseScore (1, 2, 3), then some keyboard shortcuts don't work anymore, e.g. Ctrl+Shift+End to mark a staff to the end. It drove me crazy, thought it was all kinds of things (keyboard drivers, Windows, Musescore, viruses etc.). I didn't think another program like Opera could be to blame.
So here's the hint to all those who have the same problem.