I created a new project and insert another audio file and it worked. The audio file was an .mp3. I converted the audio file I need to use to an .mp3 and it worked on my laptop, but will not work on my iMac this morning.
Adobe After Effects CS6
Running Mac OS X 10.7 also tried it on Mac OS X 10.8
3.1 GHz Intel Core i5
12 GB of Memory 1333 MHz DDR3
All programs are updated
My After Effects is freezing every time I try to scrub the play list and listen to the audio using the Command scrub option. I was using an .aiff, .wav, and mp3.