I mostly use Realtracks when working with BAIB. Without the "Send MIDI Data to Embedded Synth" It is a hit & miss situation where most tracks will not play, specially the drums track. I thought this may be ASIO issue as stated before. but everything works fine with the "Send MIDI to Embedded Synth."
However there is another issue, where the Vst pluging will stop re-generating tracks, if you are doing this a lot in one session. meaning, I have to restart the program to continue working with it. Could this be a bug?