I am working on a mac and kept getting dissed with errors preventing me from building. Rig notes errors and other stuff, preventing me from building after taking a snapshot, so I exported the mesh and rig (selected objects) as an ascii. Then imported the ascii into a new blank Maya file. That enabled me to continue. I did not select the blend shapes but they came along with the mesh in the ascii file anyway,nice. Just limit your blend shapes to one or two nodes, Not three or four (i.e. a Mouth phoneme blends node, a tongue blend shapes node, and an upper teeth blend shapes node,and a lower teeth blend shapes node. That seemed too much and they may not all make it through to unreal.) When I Opened a new blank Maya file, then IMPORTED the ascii, I then opened the art tools menu and continued,…and it worked 
I was able to build successfully after taking a snapshot. So happy:) Also, delete “:” in any names before you make the ascii. Like change "Head:polySurface " to “HeadMesh.” I guess exporting, then importing the ascii is a hard core way of file optimizing of unused nodes and other issues, … it worked. Also be sure to delete history, freeze transform and center pivot any mesh before you rig.
My question is, does anyone know how create leaf joints for an eye look (aim constraints on eyeballs to something) as well as How to use set driven keys for blend shapes, I am guessing driven by leaf joints instead of Nurbs? Otherwise I am using a timeline node to animate blend shapes of phonemes in unreal, and there may be a better way.
Many thanks for any help