Last night, I downloaded a bunch of CDLC's ranging from metallica all the way to AC/DC. (After purchasing the need Churub Rock.) Last night they all worked ant played perfectly, but I had to reinstall the game since steam didn't recognize it in my libary. So I deleted all the old Rocksmith files, and just added the CDLCs after the game installed. However not one of the CDLCs work, the official songs still work fine making me think this is a simple file issue. But I don't believe that songs I just played less than eight hours ago, across two entire albums fail to work with the "track" not appearing leaving a blank wall in the background.
I've closed and restarted the game. moved all the songs from my CDLC folder (which resided in the DLC folder) into the standard DLC folder along side the official DLCs. Then restarted both Rocksmith and my computer. At this point, I have done everything, I can think of.