Problem Texture

Hi all, I have a small problem, every time I want to put a Material for the soil or texture for wall or objects, the texture applies but does not want to be displayed and always remains in basic, I try with a autrepack and nothing changes , I do not know what to do, here is some screen:

   1. (example) before sliding the Material M_Ground_Grass into landscape:

Https://image.noelshack.com/fichiers/2018/06/7/1518347800-my-snapshot-1.jpg

   2: Just after sliding the material into the landscape (look at the material at the bottom and in the landscape, the grass texture disappears after having moved it)

Https://image.noelshack.com/fichiers/2018/06/7/1518347803-my-snapshot-2.jpg

   3: In the editorial

Https://image.noelshack.com/fichiers/2018/06/7/1518347806-my-snapshot-3.jpg

I m not sure if this helps but you should wait and let unreal compile your shaders first.

After that you should be able to see your materials.