Many thanks CR! All 50 MIDI tracks had their inputs switched to NONE! Very strange. I hadn't even been touching the MIDI side of the session, just the audio, and had suffered a couple of crashes while calling up audiosuite plugs. No idea why??? Anyhow, I guess this may have corrupted the MIDI inputs. Anyone else suddenly lost their MIDI input assignments? I know it can happen if you alter your OMS Studio Set-up to something different from your session. Thanks again, Phil 