Animation that exists on multiple layers may not export.
The 3ds Max FBX Plug-in conditionally supports Biped animation layers. If you highlight a layer and export it with the Media & Entertainment default preset, you will only export the animation from that specific layer.
How can I export multi-layer animation?
As long as you are at the uppermost (top) layer, and use the Bake animation option in the FBX exporter, you can export all animation from the top down on the layers that reside beneath the top layer.
If you do not activate Bake Animation, only the top layer of animation is exported. This is because the 3ds Max FBX Plug-in Bake Animation option scans through any unsupported controllers in 3ds Max and then re-samples the animation for export.
You can find the Bake Animation option in Include > Animation > Bake Animation.
