Mesh vertex count differs on Mac/Windows

I have a very simple mesh which is 10 vertices/8 triangles in 3DS MAX. Once imported (as FBX) into Unity, the SAME file is 13 vertices/8 triangles on my windows boxes and 10/8 on mac computers. I have disabled all import settings such as mesh compresssion/optimization and uv generation.

What on earth is going on and how do I fix it? I need this mesh to be identical so i can edit the vertices during runtime (without compiler specific code… ugh)

Attachment is the FBX file in question.

[1063-innercorner.zip|1063]

I guess i know what is different :wink: One time you selected Tangent: Calculate and one time you imported them. When you import them, it seems you have different tangents on 3 usually shared vertices. So decide what you need / want.