Issue detected : You can't add your own textures to create your personalized material because the "More" button don't show up

Cause of the issue : You're trying to modify an existing material instead of a new one

How to solve it : 

  1. Click on the Pipette
  2. Select a random material 
  3. Click on the little squares on the bottom right of the ball preview
  4. Go to the top of the list and click on the big "+"
  5. Apply this new material to your surface by a drag&drop on it 
  6. Add your textures images in the different options