I am pulling my hair out trying to figure this out... I've searched tons of threads and no luck. Since it works with history deleted, except skin weights are lost... there must be some way that this works.

EDIT: I have now even tried exporting skin weights, deleting all history, rebind mesh parts to skeleton, importing the skin weights, then export to fbx. And it still leaves seams between meshes when imported back in.

EDIT2: Froze the normals, that didnt work either. Seems to be some information in the skin weights thats not being exported. Maybe I have to freeze normals before painting weights? Hmmmm....