Hello, first time poster!

Making some jazz backing tracks, I just ran into one of my files that seems to refuse to play any RealTrack basses. I seem able to switch over to midi basses fine, and other files don't seem to have this problem. I've tried just about every RealTrack bass (and style with a RealTrack Bass), checked the preferences, the mixer, etc. but can't seem to track down the problem. Any ideas would be appreciated!

Using 2013 Pro on Win 7, if that might be relevant.