not able to build my first game in unity , blank screen ..

I followed all the instructions to make the game “Roll a Ball” and the game runs fine in unity editor but when i build it , after that screen is just greyish mud color , the game is running in the background but i cant see anything , the reason i know that the game is running is because the count still appears on the screen ( how many boxes i collected ) , as a beginner i really dont understand whats wrong , any help would be appreciated …

i changed some textures on different materials and now its working , but i still don’t know what the original problem was , probably some stupid beginner mistake .

I had the same problem. I fixed it by changing using legacy shaders. I added new materials to the player and the walls and used legacy shaders. It seems this is a problem with old PCs.