errors only appear after i play the builded version of the game

so i am making a multiplayer game so when i play it normally in the scene i get zero errors player is able to shoot fine but after i build and run I enter the game and i start shooting some areas i am able to shoot in some I am not and when I shot in the areas that I am not able to shoot in I get a nullrefrence error that's not completed so i can know the problem also this is a 3d game in unity version 2021.2.10f1