Flutter W/System.err(11906): java.lang.NullPointerException: uri

So I'm building an application to change the default ringtone. For this reason, I got this button:

onPressed: () async {      String result;      try {          result = await RingtoneSet.setRingtone("a.mp3");      } on Exception {          result = 'Error';          }      var snackbar = SnackBar(content: Text("$result"));      Scaffold.of(context).showSnackBar(snackbar);  },  

Which is created according to instructions on the plugin's site. I added all permissions in AndroidManifest.xml and all dependencies in pubspec.yaml, and even tho when I click on the button I get the confirmation 'success' message instead of 'error', my ringtone still doesn't change and I get this error:

W/System.err(11906): java.lang.NullPointerException: uri  W/System.err(11906):    at com.android.internal.util.Preconditions.checkNotNull(Preconditions.java:128)  W/System.err(11906):    at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:1275)  W/System.err(11906):    at android.content.ContentResolver.openOutputStream(ContentResolver.java:1055)  W/System.err(11906):    at android.content.ContentResolver.openOutputStream(ContentResolver.java:1031)  W/System.err(11906):    at acr.rt.ringtone_set.RingtoneSetPlugin.setThings(RingtoneSetPlugin.java:109)  W/System.err(11906):    at acr.rt.ringtone_set.RingtoneSetPlugin.onMethodCall(RingtoneSetPlugin.java:145)  W/System.err(11906):    at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:233)  W/System.err(11906):    at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(DartMessenger.java:85)  W/System.err(11906):    at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(FlutterJNI.java:692)  W/System.err(11906):    at android.os.MessageQueue.nativePollOnce(Native Method)  W/System.err(11906):    at android.os.MessageQueue.next(MessageQueue.java:326)  W/System.err(11906):    at android.os.Looper.loop(Looper.java:160)  W/System.err(11906):    at android.app.ActivityThread.main(ActivityThread.java:6669)  W/System.err(11906):    at java.lang.reflect.Method.invoke(Native Method)  W/System.err(11906):    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)  W/System.err(11906):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)  

Thanks in advice for helping me to fix it!

https://stackoverflow.com/questions/66702490/flutter-w-system-err11906-java-lang-nullpointerexception-uri March 19, 2021 at 12:28PM