Hello. It is difficult to try to help you with so little information.
For example, does the message say "game.exe" or do you mean "game" to refer to different games?
Do you use the itch app or download the games from the website?
Does it happen to you randomly or only with some games?
If it only happens to you with certain games, it is best to contact the creators of those games directly.
If the message says "game.exe" and it appears randomly, it is best to install and run an antivirus, each game has its own name and if it fails it should tell you something like <game name>.exe stopped working and not "game.exe", that could be a virus.