ive got a problem:(

sometimes i spend months making a game and what i do is i want to upload it to my meowbit but most of the times i forget to download it for a while because when i try to dowload it it just syas “compilation fail,please check code for errors” and once it says that it completely breaks the game on the simulator so when i try to play the game,all sprites and tilemaps are just gone and i have to redo most of the work ,this just happened to me on working on a mutiplayer game