I have a character that I have attached weapon bones to. For this test I only had 1 bone to make sure I have everything reset correctly. 

I freeze all the transforms and rotations before export. I take it into 3D Exchange and the Tpose is correct. I check the base export in UE4 the Tpose is correct. 

I convert to non standard character and add the weapon bone. The base skeleton is the character creator bones so the mapping is automatic. 

In Iclone everything is positioned correctly. And I apply a walk animation that shows all the correct movements. I collect clip and send it to 3DExchange with motion plus option. The animation plays there correctly no odd offsets. 

I export the animation. And import it into UE4 the animation offsets the weapon bones. 

I try exporting the exact mesh from 3dExchange thinking maybe some kind of alignment happened after importing and this still shows the same rotation issue. 

Does anyone have a clue to what this could be? I've tried several test cases trying to pinpoint where this issue is happening. 

Anoither note: If i export the character from IClone as a Unreal FBX the animation is not messed up in anyway... I'm not sure why this is the only way I can get the animation data to the engine correctly and not via 3D Exchange.