In the middle of working in Lightroom CC yesterday, it suddenly froze up and shut down. When it re-opened, it welcomed me to the new version. This has never happened - I always update manually through the CC manager app. A bunch of preference items reverted to defaults, which I discovered and corrected, except that I don't seem to be able to change the thumbnail size in the filmstrip across the bottom anymore. But my Flickr publish service disconnected from my account and it won't let me re-authorize.