AE CS6 WONT OPEN!!!! Last log message was: <140735275870560> <GPUManager> <2> Sniffer Result Code: 3

Ok, I have fixed the issue and After Effects works great now! The issue was because I was using a PC Graphics Card in my Mac Pro... It is an ATI Radeon HD 5450 1GB by ASUS and it was not being reconized correctly.

So here is the solution (THIS IS FOR AMD/ATI CARDS ONLY AND HAS ONLY BEEN TESTED WITH THE 5450):

1. You need to first make a cloned backup of your drive. We will be playing with system files and I cannot say for all certainty that you'll be able to boot the system again, so make a copy to an external drive with Carbon Copy Cloner so you can later restore if everything goes wrong.

2. You need to, if your not already, be on a fresh install of Mac OS X 10.8 Mountain Lion.

3. We need to now figure out the Device ID, Vendor ID and code name of your graphics card. To do this open up System Information and look under Hardware > Graphics/Displays and Write down your Device ID and Vendor ID. My device is 0x68E1 and My Vendor is 0x1002. Now go to http://en.wikipedia.org/wiki/Ati_gpu#Comparison_table:_desktop_GPUs and search for your Graphics Card and Write down the Code name for it, mine is Cedar.

4. Now we need to Download a tool called "Kext Wizard" and have it ready.

5. Navigate Finder to /System/Library/Extentoins and copy AMDRadeonAccelerator.kext and ATIxxxxController.kext (Replace the "xxxx" with the series card you have, I have a 5450 so I used ATI5000Controller.kext, if you have a 6850 then use ATI6000Controller.kext and so on)

6. Now Right Click on the ATIxxxxController.kext and select "Show Package Contents" Look inside the contents folder and open Info.plist with TextEdit. Inside of this document there are is a lot of code, look for the Phrase <key>IOPCIMatch</key> and following that should be a bunch of device ID's in between the "<string>" and "</string>". Now after the very last set of ID's, just before the "</string>" we will add our device ID along with our Vendor ID in this manor: 0x68E11002 (This is just Device: 0x68E1 + Vendor 0x1002 = 0x68E11002) and save that file.

7. Now Right Click on the AMDRadeonAccelerator.kext and select "Show Package Contents", Look inside the contents folder and open Info.plist with TextEdit. Now be for we add that same ID to this file we need to know the Code Name to our Graphics Card, you should have wrote this down in step 3. Again mine is Cedar so we will be looking for the line <key>AMDCedarGraphicsAccelerator</key> if you have a Cayman code named car the look for <key>AMDCaymanGraphicsAccelerator</key> and so on. Under that a few lines you should yet again see IOPCIMatch with device ID directly below it. Put your in exactly the same as you did in step 6 and save the file.

8. Now open Kext Wizard and hit Installation at the top, drag both of the .kext file on your desktop into the box and install (Make sure backup kexts is selected)

9. Once step 8 is done hit ok then Maintenance at the top and check "Rebuild Cache" and hit execute. Once down hit ok and reboot, now hope for the best.

If you cannot figure it out, Reply back here with a screen shot of System Information and what your card is and I will patch the files for you! Hope this helps! (To test if the fix worked or not try to open AE, if that fails try to open Chess or DVD Player, if they all fail then something didn't work right)