I solved this problem by fixing the fbx file. In my case, the error occurred after exporting fbx from zbrush. I’m using 3ds max, but even re-exporting the model from zbrush doesn’t help.
I fixed this by selecting all the polygons in edit poly mode, then detach it. After this, the smoothing groups are lost, but most likely this is not a problem.
I haven’t tested it, but I advise you to export the mesh in obj format and only finally export it to fbx via 3ds max or better maya