I totally think this is correct...
Odd thing is I've had LOTS of short clips open simultaneously on other projects ...recently... that didn't crash.
All in all ... I believe Melodyne in multiple instances is causing this.....
What I did was correct the problem(s) ...export the file ... then remove the region FX in preparation for the next edit.
Thanks Beepster for sticking with this one!! Hope I can be of help on something sometime!