2D tilemap Terrain/Lighting - Masked Deafult Lit

What I have been trying to do is a top down style rpg, where the tile map terrain is using the Masked default lit Material. When i play in the editor and or a new window everything is fine. i can see everything and all is well.
When i bounce the game (pack it up) and play externally the terrain is no longer visible? it is visible when i use a translucent lit material but it causes stutters.
Anyone have a solution or any ideas on how to make 2D tilemap Terrain work with Masked default lit Material?