Trying to import fbx "mesh in the fbx file is not referenced by any hierarchy node"

Anyone know what the problem is?

I have the same problem after exporting a FBX from Blender.
My FBX had two geometries and it worked fine after exporting it like that. Then I tryied to join them to make and export the FBX with the same parameters (I did nothing else than joining the two geometry as one). But now, when I try to import it in UE I have this error. What should I do to “reference the fbx in a hierarchy node” !?

Got the same error today, with one meshpart.
I solved this error first time, by joining the bad mesh to a “good” mesh, separate the parts and export as usual.

edit: Now i’ve figured out, the problem was a Material with a node assigned for cycles render! Replace this Material solved that error.

Thank you very much.
In Max I had unassigned material on the mesh and after applying the ‘Standart’ on the mesh, it’s imported very well. Thank tou!