I have a mac and a pc. When I use my PC the next time I log in to my Mac the sync folder is missing and it can't create a new one. If I restart the Mac CC works again just fine. This doesn't happen in the reverse. The PC is always able to sync and use the cloud libraries and my files. It started with the last update to illustrator. Quitting all adobe products and then opening the programs doesn't fix the problem. I have to quit the programs then restart the Mac for syncing to commence.