Import Skeletal Mesh CRASHES Unreal - or returns a failed skeleton match

Development Character & Animation
1

Took me a long time to get down to this, but here’s what’s going on:

After many crashes on importing an FBX with an existing skeletal mesh I decided to test this to the max. I opened an animation from the existing mesh in Unreal, exported it as FBX.
I can import that FBX into Unreal again and match the skeleton. Importing takes a while, but no errors or crashes.

If I open that same FBX in Cinema4D, without touching a single thing, and export it as FBX right away, it won’t import in Unreal or hard crashes Unreal.
I’ve tried every single FBX export setting you can imagine, from baking keyframes to not exporting normals, you name it.

What am I doing wrong?

2

Are you removing the top level extra bone from the rig (will have the same name as the model above root)? For some reason this always gets added on export.

3

It would make sense if that’s the case… Is that bone visible in Cinema4d? Because if it is, then it’s not there. But if it adds in on export, that would make a lot of sense as to this bug.