Ok after many tests i’ve found a solution:
This problem seems happend only when you mark seams before the creation of the checker texture !
In my case i’ve solve it like this:
You can unwrap your mesh, (without any seam) and then create the checker texture
Or you can create the checker texture first and unwrap your mesh (without any seam).
But do NOT mark seam an edge without the texture… I don’t know why but this is what cause the problem of the white mesh for my case !
