<<< BIAB 2020 (64) consistently crashes every time I try to export my song to a .WAV file. The song is all RealTracks, but I also tried other mixed files and they also will crash BIAB. >>>

You need to address this issue first. It's likely also to be at least part of the issue you're having with MIDI.

The first thing I suggest you try is resetting BIAB to factory defaults.

The command is found at Options\Return to Factory Defaults


BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.