Same problem here on a PC, not mac. If you launch Premiere Pro CC and try to export to AME, AME crashes and 2 out of 3 times, this causes PP to crash.
If you lauch AME ahead of time, it normally doesn't crash when you export from PP.
This never happens with CS6 counterparts.
AME CC and PP CC are also a backawards step for those of us who still produce DVD's for clients. I think it's arrogant of Adobe to think that just because they don't do discs, that their clients won't either.