I don't know if this is a CbB issue or Kontakt 5 or Epic Babies or all three, but...
I've been trying to use Epic Babies by PulseSetter Sounds in Kontakt 5 (full addition) and everytime I stop the recording engine in CbB, I lose all sound in this particular library. The only way to get the sound back is to close the library (not Kontakt) and reopen it. But as soon as I stop the recording engine again, I lose sound.
As I don't appear to have a problem with any other library, I think it may just be that particular one.
Has anyone else come across this problem before?