Bringing a clothed CC character back from Blender I get this error.
Seems to only be happening with a new fully clothed character.  
No modifications were done to the base mesh.
Clothing was modeled and married to the rig per this course: 



... and exported from Blender as instructed... All the settings, exactly the same.
And I'm careful to include the fbx key file on import.
I receive this error if I attempt to FILE > IMPORT or CREATE > CLOTH
As you can see from my screenshot below, everything is selected before export... all the bones... all the meshes... 



That being the case, I don't know what this error even means: 



Incidently - this doesn't seem to be a problem for 3DX7:



Hello again, and thanks in advance ;)