In Blender, try Mesh/Normals/Recalculate Outside. The gun isn’t attached to the hands, so you may need to export the two meshes separately anyway. If this doesn’t work, then you should check that your export settings are correct.
In Blender, try Mesh/Normals/Recalculate Outside. The gun isn’t attached to the hands, so you may need to export the two meshes separately anyway. If this doesn’t work, then you should check that your export settings are correct.