iCloud Drive isn't compatible with OS X Mavericks
I just upgraded to the latest Numbers on my iMac, and now when I try to open a spreadsheet I get the following error message:
Sorry, iCloud Drive isn't compatible with OS X Mavericks. You've upgraded your account to iCloud Drive. To keep your spreadsheets current across all your drives, update to OS X Yosemite.
Yosemite hasn't even been released yet, what am I supposed to do? I had no idea I upgraded to iCloud Drive, how do I downgrade?
iMac, OS X Mavericks (10.9.1)