i'm always surprised by the number of people claiming that 4gb isn't enough for big files. i mean, i realize they don't know that FL uses a 2gb or 3gb limit depending on if you use the switch executable or not, but still, i've maxed out FL studio once. if you're using more than that, just render a track out as an mp3 and use that instead of the memory-hungry vst that you're using.
not to mention fl 9.5 has way better performance with limited resources.
but yeah, OP, you've gotta be using like if you've got VSTs that use 50mb a piece, you're using like 40 instances of them to max it out. get simpler
seriously, though, your issue is likely related to the 2gb limitation that FL has. use the 3gb switch .exe in your FL directory, and you should be able to render.
edit: you all know that image-line has a program that allows you to disable corrupted plugins outside of FL on your .flp files so that you can load a corrupted file, right? it'll just open that channel as a sampler or something.