I have had this error before, I forgot how to fix it. Every time I try to RAM preview a project I'm working on, it stops at the end of the first layer, here's a screenshot:
I'm not sure if it is the pre-comp of the next clip doing it. If i go to the start of the layer that doesn't render, I can preview it, but nothing after it.
I don't get any error boxes or error codes (When I used to, last time I got this problem)
16 GB Ram, Intel Xeon X5355, 64 Bit OS