OK, so Ive read a lot about this issue with a PC and seen the fix for it but have not been able to find the fix for a Mac. Has some one had this issue and fixed it some how. The files have been correctly converted to m.psarc. and I have much less than 250 songs in the dlc folder. Its only a few songs I don't know what the issue could be.

But then sometimes when I start the game some of the missing titles are there then gone the next. very strange. I don't get it. 

I am having the same problem, haven't been able to find a fix on here. I have about 250 CDLC in my dlc folder. About half of the songs show up in game and work fine, but the other half will not show up in the game. I've redownloaded and reconverted them, emptied my dlc folder and copied it back, but I can't get a lot of my CDLC to show up.

Sounds like you have a bad custom, or some customs that are conflicting with each other.

 

Remove all of the customs from your dlc folder and add them back in small batches until you figure out which one(s) are causing the problem.