First of all, always check if the model's normal surfaces are facing at the correct direction.
Troubleshooting Bi-Normals Error (left):
cause: bad UV
Link that could help:
https://www.youtube.com/watch?v=Vz8Ne5perio
Mixed shader in Blender DOES NOT apply to the model when exporting as FBX
Reworked the entire material of Kassadin Sword on UE, will simplify material if required (performance)
Comparison between old(left) version on Blender and new(right) version in UE. Yes I do sometimes prefer the style on the left but hey it is what it is. The new version kind of gives us the "pre-rework Kassadin" feel.
Check Out This Object
On the right is the current setting I'm using when exporting models from Blender to Unreal Engine, source below:
https://ragatol.github.io/artigos/FBX_Blender_to_UE4/en.html
USE THIS ONE ON THE RIGHT ->
scale the rig to 100 in Blender then apply. then scale it back down to 0.01
don't use the default Blender metarig name.
setup a root bone
Uncheck this circled option when exporting (under animation)
online resource
online resource