I copied the 'Classic' UI schema and changed it to make my own schema. Among other things, I changes the sprite of the grid cell ( Inventory, Hotbar ), in the 'Item View For Grid' prefab. While in the scene view everything seems to be ok, after starting in the game view the cells are painted with the default sprite ( see screenshots ). After hours of seaching for the problem, I changed the sprite in the original Opsive classic schema, then my own sprite was drawn. It seems this prefab is taken from the original schema and not from the copied one.