El capitan and Imovie 10.1 not recognizing firewire camera

I recently upgraded to El Capitan and iMovie 10.01. My Sony camcorder is no longer recognized. Went though 10 hrs of Tech support with Apple and finally got a senior advisor. We reset PRAM and SMC, and briefly got it to work, then it failed again and iMovie keeps crashing Tried the camera on another mac with iMovie 10.09.9 and it worked fine. Advisor agreed there is bug in iMovie 10.1 When He passed me over to Senior advisor for Apps. i was simply told my camera is not supported which is baloney. The really ***** for those of us who make movies for a living. Would appreciate hearing how to get this escalated and fixed. I'm sure that Apple will probably run an update for the issue if any one else out there is having the same trouble, please post. Thanks