I’ve only seen this message in the record monitor when I tried to use many different P2 or XDCam card folders via AMA without transcoding. That was on MC 3.5.1 on an Adrenaline without HD, so it was all software only.
Is all your media Avid-native, or do you have tapeless camera media linked into your project through AMA?
My only solution was to transcode or consolidate media to Avid DNx.
brian