Why can't I play the audio file using startAudioMixing or playEffect on Android 9?

Issue description

Cannot play an mp3, mp4, or any other music format using startAudioMixing or playEffect on Android 9.

Reason

This is caused by an Android permission limit. If targetSdkVersion ≥ 28, you need to add relevant app privileges to play the a music file.

Solution

For Android projects with targetSdkVersion ≥ 28, add the following line in the application zone of the AndroidManifest.xml file to play the music file:

<application
   android:usesCleartextTraffic="true"
   android:requestLegacyExternalStorage="true"
   …
</application>

Relevant links

For more Android permission settings and considerations, see Project setup.