I am attempting to edit a skyrim mesh, I open the mesh in nifskope export it as obj and open it in blender. I edit the mesh then export it as obj open it in nifskope but when I try to save it as a nif file so I can open it in creation kit it I get an error message saying block 4 Tangents array size mismatch, block 4 Bitangents array size mismatch, block 10 Tangents array size mismatch, block 10 Bitangents array size mismatch. I can view it in nifskope fine I just can't save it as a nif file this is the first time I have tried to use blender.