Material not loading

Hi I have a project that I created at home on the latest version of Unity. When I tried to run it at school (which have an older version of unity) the materials didn't load. I reloaded them and they worked on the other objects but I have an object left that the material didn't load. You can find a picture here:

As You can see the material successfully loaded in the inspector but not on the object. I did the same process as I did on the other ones but it's not working.

Can someone give me a solution please?