I use after effects cc 2014 on my macbook pro version 10.9.5 2.6GHz intel core i7. Memory 16G 1600 MHz DDR3. Nvidia GeForce GT 750M 2048 MB.
Recently, almost every time I try and do a Ram preview using the button in the preview panel, my computer pauses and appears to not register then when I move the mouse it beach balls. If I wait and watch it it, it suddenly shows green but doesn't play back. If I hit the button again it does it all again. If I hit space bar to play it doesn't play the audio. It does scrub fine. If I go on to another program while it is previewing it lets me know when it has done but isn't playing and if I hit the button to get it to play it does it again!! It does occasionally work but more often than not it doesn't.
I have tried all the usual restarts and purging the cache.
The comp is a 25fps 1920x1080 and I am using 3D but the comps aren't huge.