There ought to be a sticky post about what users should do when Pr stops working.
First off, eliminate your computer as the problem. Permissions, Disk Warrior, RAM check, etc.
If no help, start with relaunching the app.
If no help, reboot the computer.
If no help, reset prefs (Hold option while launching. Hold option-shift to reset prefs and dump caches).
If no help, try a new project or different media, to eliminate your source footage as being corrupted.
If it happens with any and all projects and footage and fresh prefs, uninstall and reinstall the app.
If no help, post your issue to the list.
If others are having the same problem, file bug report.
Pretty much all done - and it's happening on different footage on two macs <sigh >
Yup, did all that - hence posted on the forum. So, anyone else having this problem?
How about posting your system specs? I have a MacPro3,1, 32G RAM. Quadro 4000 with native drivers on Lion (not the Nvidia driver). I'm not having problems exporting H.264, but I'm mostly doing :30 spots.
We Mac users should have our own forum. When I open a thread that reports a CS6 problem that I'm experiencing on my Mac, 9 times out of ten it's from another Apple user. If the bugs are embedded in CS6 for Mac, which I suspect they are, maybe people could avoid wasting time trying to debug their systems and avoid spending money on hardware or changing things that do work in a vain effort to get things working. (I think Dynamic link and Media Encoder would turn out to be behind 90% of the complaints, but that's just my hunch from poring through posts.)