Failed to Merge Bones

I was trying to import a model (monster0622.fbx) with morph targets into UE4 as skeletal mesh. The skeleton I’m using is the one in Generic_Skeleton.uasset. Every time I will get this error message during the import.Can you please help me out?
FAILED TO MERGE BONES:
This could happen if significant hierarchical change has been made…
link text

Well I downloaded your mesh and the issue seems to just be vertex groups. There was no weight paint on the mesh as far as I could tell, could just be the download. When its importing your mesh and trying to force the skeleton on it, it doesn’t know what bone is supposed to control which vertices. Again I’m not sure if it was the download, your mesh didn’t have any skeleton. Another issue that I’ve run into is a mesh that is comprised of more than one scene OBJ on export. For instance you have the eyes and the head and the body and whatnot separated, I’d recommend keeping them separate until export, for easy modifying, then combining all before exporting manually, not during.

My issue came when I tried to keep the eyes of my characters separated for ease, every time on export it would only get the armatures for the eyes. I think it could just have something to do with combining armature hierarchies on export, but I find pretty much a 100% success rate when all scene OBJs are combined and the armatures are combined and parented through one contiguous mesh, just keep the elements you want separated by using separate materials for easy selection and texturing. I would just build a skeleton from scratch and keep a blank for when you need it.

Thank you very much for the help!

I have figured it out thanks to your enlightening answer. I was not aware that morph targets need to be created on a skinned model in order to be accepted by UE4. There’s no problem with your download - the model does not a skeleton. It works pretty well now after I had it skinned.

Again, much appreciated for your help!

Hello Hope you would be doing great

I am having the same issue with unreal engine mannequin rig in blender when I re export it in unreal engine.

Could you please help me out as I am quite with that problem for a long time.

Thanks