Fix Flutter Error : Cannot resolve symbol for properties and Gradle exception

Have a problem on Cannot resolve symbol for properties and Gradle exception. Follow with me : 1- File : Project Structure Under Project Settings/Project : Set Project SDK to Android API 29 Platform 2- here should be a notification stating there is an invalid item in the dependencies list under Project Structure/Problems. If there is, go to : Project Structure Under Project Settings/Modules select app_name_android Dependencies tab choose the latest "Android API 29 Platform" in the Module SDK box. 3- Update GradleException() to FileNotFoundException() under android/app/build_gradle since it's not supported in the Java version of Android API 29.