Menu Bar becomes invisible


I am currently running Cubase 9. I have had a strange issue since Cubase 8.0 where the menu bar becomes invisible after Cubase has been left running for a day or two. If I click where the menu should be, the menu appears but the rest of the menus are not visible. So I have been able to work even where this is the case, because I know where approximately the menus are on the screen, but it is a bit of an annoyance anyway.

Any way to fix this?

Don’t let it run for days on end.

I wouldn’t normally, but I have big complex projects that take a while to load and prefer to leave them loaded rather than closing down each night. Cubase still works reliably in these cases, other than the menu bar issue. I would like to get that solved.