Just installed the update to cc 2014 did a couple of hours work and cant save anything to any drive, internal or external. Keep getting the same error message which says the drive is not available. Nothing wrong with drive and i reckon the permissions are all good Having spent a couple of hours on the support chat with one of the guys I'm going a bit barmy. Surely someone else has had the same issue?
If you're still trying to save your work, you might try duplicating the image and saving it from a separate document.
What are your scratch drive settings?