Any chance the files went corrupted when moving them? Can You play them with VLC or Telestream Switch? What is the size? Can You get them again from the ISIS?

I can play the video in VLC and import it into Premiere as well. The audio produces no waveform and no sound in either VLC or Premiere. The audio files are about 60MB each, the video almost 2GB. I can't get them again from the ISIS but have complete raw backups obviously. They still show up as red/offline in Avid. It's possible that the files I'm looking at are the bank audio that was important with the raw camera media (that was told by RedCineXpro to include, rather than turning off the audio option when there isn't any on the R3D file) and not the MXFs generated from raw production audio I suppose. Can't recall/figure out how to match back to the originally imported audio files.

How did You brought in the footage in the first place? If old fashioned import just delete the offending audio files (do not flush the trash, just in case), and batch import again. If it was linked and transcoded, do it again and forget about the non working clip, You'll have perhaps to delete it and relink the sequence to the newly created clip. If nothing works, as a workaround, convert the files to WAV with VLC or Premiere, import back in Avid and sync to the video clip. HTH