Hey fellow Mac users. I updated to Yosemite today and the good news is that Rocksmith still works great with all of the CDLC. Nothing seems to have changed. The bad news is that my customsongtoolkit no longer opens. It was working perfectly fine before the update to Yosemite. I have downloaded several of the previous releases to test and received the same result. I also reinstalled Mono. Basically, it spins the beachball for a moment, appears in the dock and just hangs. It needs to then be fo