Just downloaded and installed new LR CC. No apparent problems with the D/I on my iMac, OS 10.10.3. however LR CC will not start. I get a momentary flash of the opening screen and then the program shuts down. From the posts it looks like this if a very common problem. Any help would be appreciated. Thanks.
Have you tried logging out of your CC desktop app, then logging back in again? Quit/Restart won't work, but logging out and back in should. See here: https://helpx.adobe.com/creative-cloud/kb/sign-in-out-creative-cloud-desktop-app.html
Thanks Jim, Your help solved the problem. LF CC working fine.