A FBM dial that just spins to no effect upon loading usually means you dumped the group info somewhere along the import/export.

In Blender import make sure not to split the obj, make sure vertex groups is selected, and maintain vertex order. It's not a vertex order problem however, you'd end up with an exploding morph if that were the case, still you'll want to maintain vertex order in all import/export instances. Likewise it's not a wrong number of vertices error (which would be the result of splitting the mesh).

On export make sure Vertex Groups and Vertex order are selected in the export options, "typically" these are the only 2 options that need to be checked for Blender export of obj for FBM purposes...