Some forum members use Cakewalk's TTS-1 32 bit soft synth as their default MIDI sound source in Band-in-a-Box.
Did you know: Ucheck all midi outputs in preferences and TTS-1 will automatically load up when you OPEN any midi file. Makes it super easy to preview midi song files.
I found this little nugget in a Cakewalk forum post.
I'm old and slow, so can you explain "uncheck all midi outputs in preferences"?
Your image shows the only 2 check boxes available as checked .. and I think they need to be.