where is the problem?
i got error:
Information:Gradle tasks [:app:generateDebugSources, :app:mockableAndroidJar, :app:prepareDebugUnitTestDependencies, :app:generateDebugAndroidTestSources, :app:compileDebugSources, :app:compileDebugUnitTestSources, :app:compileDebugAndroidTestSources]
C:\Users\Sanver\Desktop\flarum-mobile-android-master\app\src\main\java\org\flarum\flarum\FCM\MyFirebaseMessagingService.java
Error:(15, 25) error: cannot find symbol class R
Error:(50, 32) error: package R does not exist
Error:(49, 94) error: package R does not exist
C:\Users\Sanver\Desktop\flarum-mobile-android-master\app\src\main\java\org\flarum\flarum\MainActivity.java
Error:(34, 25) error: package R does not exist
Error:(35, 51) error: package R does not exist
Error:(38, 45) error: package R does not exist
Error:(40, 51) error: package R does not exist
Error:(100, 36) error: package R does not exist
Error:(112, 20) error: package R does not exist
Error:(119, 27) error: package R does not exist
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
Compilation failed; see the compiler error output for details.
Information:BUILD FAILED
Information:Total time: 2.676 secs
Information:11 errors
Information:0 warnings
Information:See complete output in console
Edit: actually i bypass the problem with make the name of package name "org.flarum.flarum" on developers.google.