Thanks for the scene. I'm testing it, but cannot find any problem. Except "Forest009" which doesn't render because has not include areas (Forest shows a popup message after rendering).
I used FP 4.4.1, V-Ray 2.20.01 and Max 2014 SP5 (this is the only difference with your render nodes, which have SP3).
I'm afraid the only way to isolate the problem will be by trial and error, modifying and rendering the scene at each step. I suggest to do it interactively in one of the problematic render nodes:
1) First, be sure that "General->Disable Pop-ups" is off, so Forest shows render errors if any. This parameter is global for all Forest objects.
2) Delete non-essential objects, keeping Forest and related items (areas, cameras, lights and so). Besides render will be quicker, this configuration should discard errors by high memory use.
3) I see all Forest objects use proxies. Try replacing them by a test mesh.
4) Try saving and rendering the scene with Max 2016. Does it solve the problem ?.
We can try other tests, once we have the results from these.