Hi, it's difficult to know what is causing the problem, because there are many components involved. Futhermore, many of them are deprecated versions (Max 2011, Deadline 5, even V-Ray 2), so probably you are missing multiple fixes from the latest updates.
If you can get a minidump
from the crashes, we would have more information. If not, i'm afraid there is not much we can do.
Animated FP objects require more resources and processing time than static models, because the plugin must request several samples for each one of the objects. Although this should not cause crashes.
Processing time depends both of the underlying object and the mesh size. According to our tests, the faster format is V-Ray proxy (although it has some limitations, as not support for Element mode in Forest Color).
Does every render node need an independent graphic card for rendering the complex animated forest objects ? There is no independent video graphic card in most of my render nodes. They have only low-end integrated video cards.
No, graphics card is not used in any way for rendering. Only CPU and RAM.
We found a serious problem after long time render. The big trees Xmesh sequences in forest objects kept frickering in DiffuseFilter pass because of the Forest Color map of the leaves.
We should do some tests, but i suspect problem is caused by XMesh. Forest Color requires that the geometry structure of the tree don't change along all frames: i mean, that the number and order of vertices and faces be identical (although they can be moved or transformed). I remember that XMesh uses a very particular format to store the animation, so i don't know if it meets the above rule.
What XMesh version do you use ?