My Galaxy M30s was facing problem after 01 October 2020 security update this month.All My Apps were getting crashed immediatly after opening app. Finally i found few problems due to which this was happening in my mobile.
Reason 1: Android System Webview App was getting updated in my mobile with other user (Seconday mail id) in my mobile due to which this app was not getting updated with all other apps. Which was leading to app crashes. So finally found this and updated with the secondary mail id after that apps are working fine.
