"App was unfortunately ended" after opening it on android

Hello fellow developers,

i just made my first app and published it for android in the google play store. That all happened without problem. But after downloading the app on my second phone (android) and trying to open it. The App shows a blank screen and closes with the message “App was ended”. During live testing everything was fine and also the version for iOS works fine with testflight (in review process ATM).

Do you guys have any idea what could cause the crash?

Thank you already for all the replies.

Best regards,