I've looked all over the web, AE helps and docs, and can't find a definitive answer to this question. - Should I turn off the screensaver and/or energy saver on my Mac during rendering? I've been rendering (or I thought so) for more than 2 hours and when I came back to check on the progress it was basically in the same place as when I left. Now sitting here watching it it's moving again. So it seems obvious to me, but why isn't this addressed anywere in the AE documentation or helps?
Well, ask yourself: Would Pixar (or any otehr CG/ VFX shop) run screensavers on their machines while waiting for some renders? Simply turn those features off or at least set the timeouts so high, that it only happens after half an hour or later....
I've been using After Effects for 13 years now, and am only experiencing this problem lately. It used to be that you could keep your computer in energy saver mode. You could render a movie or frame sequence out of AE, maybe it takes 8 hours, and then when it was done (maybe at some odd time like 3am), the computer would register no activity and go to sleep.
Now it goes to sleep as if no activity is happening, and crashes the render.
Turning off energy saver will keep your render but then cost you on the electric bill: if you are away from the workstation, or managing this remotely, and the computer just stays on for a day after the render is complete.