I never have Natural Arrangements enabled.
Try this.
- Start BiaB.
- One single 'C' chord in the first cell, nothing else.
- 32 bars.
- Press Generate.
You will get this message (which makes no obvious sense to me)

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BIAB & RB2026 Win.(Audiophile), Windows 10 Pro & Windows 11, Cakewalk Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Session Keys Grand S & Electric R, Kontakt, Focusrite 18i20, KetronSD2, NS40M, Pioneer Active Monitors.