Play Mode fine, build only gray

Hi!
I don’t know how to be more specific, but all I know is that the play mode works fine but
when I build the game the screen is just gray.
I build it a few times before and it worked very well, but suddenly it doesn’t anymore.
I have added all scenes in the build settings.
Does anyone have a suggestion what I might be doing wrong?

hi;

do u mean the game is not lunching at all ?

witch platform are u building?;

and did u use any kind of image effect on your camera ?