OK, now it has become a really big problem!
It is not only the Global RenderSettings menu which goes wrong, but all the menus with this arrow on the left to hide or unhide the settings, for example Attribute editor, too!!! Some settings don`t open, some aren`t complet! But i was able to change the settigs with the command line, but this is no way!
now i need much more help!
(maybe someone can move this thread to the "Technical Issues" forum?)