Did you follow all of the instructions from the 2nd post of this thread? Steam needs to be installed in the default location, as well as Rocksmith. You also need to own an official DLC (Cherub Rock is recommended as that's the AppID most customs use). You need to purchase the official DLC from the Steam store so that it is licensed to you. You can't use pirated DLC. If you've done all that, it's possible you have a bad custom, or customs that are conflicting with each other. Remove all of your customs out of the DLC folder and try just 1 (try and pick one that is newer and from an established charter). I had this exact same problem too. I followed all instructions by the book, the new injector ran fine but every song hung after the tuning screen. Furthermore, the majority of cdlc AND dlc were showing up without their artwork where upon selecting them made them disappear. In my case, I can confirm that it was definitely a cdlc issue. Either due to a select few faulty cdlc files or just the sheer quantity of cdlc that was in my dlc folder. I too would recommend that you clear out your dlc folder entirely and add only a few back at a time, namely the ones you want to play. I stripped my library down to about 10, (the other 200 hundred or so are in a folder on my desktop) and low and behold everything works flawlessly now. I’ve since added back about 40 other select songs and still no troubles. So I’d recommend everyone else having similar problems on their mac to try the same. I reinstalled steam and the latest RSInjector and have had some success. However, after a few CDLC plays, the game freezes up. Better than nothing though!