Sprite diffuse does not work

Hello,

I have tried this tutorial, here: http://imakeinternet.com/unity-2d-sprite-lighting/
I have created a new project to test. Ok, it works well!

After, I have tried to do the same process in my “existing project” and it does not work at all. I have done the same thing.
I have set the light in front of the sprites, too.

Here is the result :
With a normal working “Sprite-Default” : alt text
With a Sprite diffuse, everything is grey : alt text

Please, someone have an idea ?
Thanks

Mitch

Solved!

It does not work because i had set the wrong camera settings:
Rendering Path: Vertex lit

By setting “Use Player Settings”, it works