So I ran into this issue recently and thought I’d share the solution since it took me a fair amount of searching to find out what was causing the problem. I installed my copy of Premiere Pro CS5 for the Mac on a second machine. Yes this is perfectly legal. I wanted to be able to use it at work and home so I installed it on my work machine this week. However, all was not well.
Nothing would play in Premiere for more than a second or two, whether it was video or audio regardless of format, and Premiere would crash all the time with a weird error. Not good. Several forums said to delete the file com.apple.AggregateAudioDevices.plst from MacintoshHD/Library/Preferences/, but I found no such file.
Adobe Forum Thread
Eventually I found this thread on the Adobe forums:
Here’s the best bit:
“the general issue seems to be that in some cases the user account in which Premiere Pro is running doesn’t have the permission to write to certain files. The root account does. Once these files have been written to, everything is hunky-dory. This seems to be entangled with some other permissions issues and writing to preferences files. This is affecting After Effects and Soundbooth, too, it seems.
So, repairing permissions and running as root are right up there with deleting the preferences folder in the list of relatively easy and harmless things to try when troubleshooting (before reinstallation and such more drastic things).”
Here’s the Solution
If you run Premiere for the first time on a user account that is NOT an administrator, Premiere can’t write certain files necessary for talking to the graphics and audio drivers and so nothing will play. I was logged in as a non-administrator user and this prevented Premiere from setting up properly.
The fix is to log in as an administrator, launch Premiere, play a clip, log out, log back in as the regular user and everything’s great and plays perfectly provided your machine meets the minimum system requirements for Premiere and the Mercury Playback Engine.