Does it do that only when there's footage in the comp or does it do it even when the comp is nothing but shape layers and solids?
If there's footage, what format and codec is it?
What third-party plugins are installed?
Does it behave if you change your preview settings? (Favors length vs. favors frame rate, etc.)
I am using Red Giant Magic Bullet Suite, Trapcode Suite, Effects Suite, and Keying Suite. All of these are the latest versions. The issue I am experiencing occurs with PNG sequences, TIFF sequences, Apple Pro Rez 4444, and probably other formats that I am not thinking about. The projects also include several depths of nested comps, adjustment layers, and solids. I haven't noticed anything in particular with shape layers. These same project files work perfectly in CC2014. The length doesn't matter. I haven't changed frame rates. But I have skipped frames. This doesn't change anything. Another strange thing occurs during rendering. The comp for the render covers the render queue, making it impossible to stop or pause a render. And the composition window doesn't update frame by frame during renders as it did in the past.
I am using a 2013 Mac Pro with 32 gigs of RAM on OS 10.9.5.
I have given up trying to use After Effects CC 2015 for anything that is even remotely important for now. I am still having the same RAM and memory related issues as before. Every other version of After Effects from CC 2014 to CS 5 works perfectly on my Mac. I am trying to determine if this is a machine issue or a software issue. I have never had problems with other version of After Effects since I started using it in 1995. I am leaning toward this being some sort of software problem. Is it with After Effects or the way I have my computer configured? Any insights would be most appreciated.