i need your help please

Hello i need your help in solving my problem that im facing in my applications that i develop on app inventor
during working on the app a msg apear " "app " has been stopped" after a while it continue working

so i need your help in solving it please



you will have to provide some more information about what you are doing in your app, else we only can guess

and my guess is, you do not switch screens correctly, the  manager screen method is the recommended method https://puravidaapps.com/manager.php