Originally Posted by Andrew - PG Music
There are two ways to fix this.

A) Turn off Natural arrangements in the Song settings dialog.

B) Use the Auto-fix (tune) on just the first half of bar 18. I tested this with your song, and it works well. This feature in general works best for specific parts of a track rather than as a setting for the entire track. You could do something like this.
1. Turn OFF the Auto-fix track in Track Settings.
2. Use Track Actions | Copy/Move Track to copy the track to Utility track 1 where you can work on it further and preserve the original BiaB generated track.
3. Open the Audio Edit window, and highlight ONLY the first half of bar 18.
4. Click on the Edit button (in the Audio Edit window toolbar) and click Fix Tuning. Make sure Song Chords is selected and OK. This will add the G# to that bar. Repeat for the other bar of interest.

Thanks for helping again Andrew.
I don't know what computer or version of BIAB you are using, but your suggestions are not working well for me.

For fix A) it worked only for the 1st chorus, not the 2nd or 3rd !!! (742 piano)
For fix B) it didn't work at all

A BIAB user for more than 30 years (if you can believe it) !