As I read your last question I understand you are using multiple styles in a RealBand song file or sequence. Is this correct?

RealBand (RB) reserves the first eight tracks for Band-in-a-Box (BiaB) MIDI tracks. However, you can use the command to make the first eight BiaB tracks regular tracks and the tracks will become RealBand tracks.

RealBand tracks default to audio tracks. When you start a song with all RealTracks each RealTrack will occupy a RealBand audio track.

If you switch styles and the new style has one or MIDI instruments the MIDI instruments will not have a track to land on unless you have previously changed one or more audio tracks to a MIDI track.

I don't think RealBand is going to automatically change an unused audio track to a MIDI track when you change to a style that includes MIDI.

Jim Fogle - 2024 BiaB (1111) RB (5) Ultra+ PAK
DAWs: Cakewalk by BandLab (CbB) - Standalone: Zoom MRS-8
Laptop: i3 Win 10, 8GB ram 500GB HDD
Desktop: i7 Win 11, 12GB ram 256GB SSD, 4 TB HDD
Music at: https://fogle622.wix.com/fogle622-audio-home