Sooo frustrating! I installed the new patcher as per this thread, and rocksmith became unplayable. EVERY song, even the built in ones, would let me tune and would then never start the song. I downloaded a completely fresh copy of Rocksmith, ran the patch, and everything started working again. Reinstall some of my DLCs, all good. Put all of them back, and I get back to the same problem. So it seems that some dud dlc causes the whole game to stop working. Now I have to disect my collection to find out which one....or ones.