I updated all my CC apps:Lightroom, Photoshop and Bridge this morning, using the CC updater. All appeared to go well with the downloads and installs, but now I can't open any of these because I get a pop up requiring me to sign in with my Adobe ID, and that screen just repeats in an endless loop. Help!
Just got through a chat with Adobe support. The solution was to go to the Program Data Folder for Adobe: %ProgramData%/Adobe, and rename the SIStore folder to SIStore_old. Some file or files in this had presumably become corrupted, and forcing a re-creation of the files and folder set things right again.