Cannot type certain symbols on MacBook Pro keyboard / external keyboard
Dear all,
I have a very severe and annoying problem. I cannot type some characters anymore. Specifically, the at symbol and the backslash do not work. When I open the keyboard view I see that the at symbol is at the right location, so when I hit the modifier "opt" I see that "l" changes to an at. Similarily, when hitting SHIFT + OPT most symbols do not work (backslash, hash etc). They are all displayed on the keyboard viewer correctly though .... I dont hear a beep when I try to type the at symbol, just nothing happens ... When I click on the symbol in the key board viewer also nothing happens. I tried with the MP keyboard, an magic keyboard and an logitech keyboard.
Any ideas how to fix this what is going wrong?
I am using QWERTZ keyboards and have verified that I have iso settings for the keyboards.