I usually work on a mac but at the moment have to work on a PC.
I have logged into Adobe but nothing is working. I have updated all the apps but when I go into something I get a white box and although I can see the program nothing is responding and all menus are greyed out? Why is that - do I need to sign out of the Mac cloud?
Probably, since you can only be logged in and actively using your subscription on one computer at a time. However, I'm not a Mac user or a CC user, so let's try you in Creative Cloud Services where someone who knows the answer is more likely to see it.
The Using the Community forum is for help in using the Adobe Support Community forums, not for help with specific programs. Product questions should be posted in the associated product community.