Maya smooth mesh disappears

I have a semi-detailed mech model with a simple walk animation in Maya via a bound smooth skin. I have deleted non-deformer history, and froze transformations prior to binding. When I import via FXB or directly into Unity, the mesh disappears. If I remove the smooth skin (and therefore animation), it imports just fine.

What potential issues could cause this? I have read that animating vertexes will. I'm not aware of having animated vertexes, but am also not sure of a systematic way to check (if I select all the vertices I don't see any keyframes). I'm thinking of rebuilding my skeleton, or perhaps using a rigid bind, but that would be time consuming and I would like to understand the root of the issue. What troubleshooting steps would be recommended?

 

OK I did solve my issue, but any input on the question would be interesting. My solution was to delete the skeleton and all history, perform a new smooth bind, and simply test my model/animation by importing at various steps in the animation and skin weight painting process. My recommendation for anyone else reading this with similar problems is test import frequently while saving the file in stages so that any issues can be identified quickly.

 

I'm having the same issue, but creating a new skeleton and smooth bind isn't helping my cause :/
If anyone knows something about this I'd like to hear it too.