What the man said. It's an issue with your graphics card/ driver, but without knowing any details, nobody can advise specifically. Update your driver, configure it properly.
Here's the specifics of my question:
Error prompt on close:
Last log message was: <140735201747328> <ae.blitpipe> <2> HardwareBlitpipe Disengaged. Generating crash log, which may take a few minutes.
- AE VERSION: 11.0.2
- MAC OS: 10.8.3
- PROCESSOR 2X2.4 GHz 6-Core Intel Xeon
- MEMORY 12GB 1333 MHz DDR3
- VIDEO CARD ATI Radeon HD 5770 1024 MB graphics
- FOOTAGE N/A - CRASHES ON EVERY CLOSE REGARDLESS OF FOOTAGE FORMAT OR CODEC
- OCCURANCE ON QUIT / CLOSE AE
- QUICKTIME 10.2
- ADTL VIDEO BLACKMAGIC Multibridge Pro
- OPEN GL NO
This error only occurs when I have worked inside a session. If I open and close AE and do not actually do any work (ie save session), AE closes without incident.
You have a conflict between Quicktime, your Blackmagic stuff and your normal graphics hardware. If even basic OpenGL isn't avialable, something is seriously wrong. Well, whatever, I'm not a Mac guy and chances are you need to ask on the BMD forums and update your drivers for the hardware to resolve your issues.