export failed error -1

It was just a couple of months ago that I was exporting my Motion 5 projects as quicktime movies with few problems. This week, I'm getting repeated export failures that occur at a different frame number each time, but usually with the error code -1. RAM previews are not especially quick or smooth either. I have rebuilt my OSX directories with Disk Warrior and repaired permissions. That hasn't helped. Does anyone have any insight into this problem? I won't be able to keep using Motion 5 if I can't resolve this. I export quicktime movies because I'm importing into Premiere Pro CC.