When I use
//Prepare player with media configuration.
player.Prepare(mediaConfig);
I was able to solve the error that is mentioned but I have a new issue
{Java.Lang.NoSuchMethodError: No virtual method addListener(Lcom/google/android/exoplayer2/ExoPlayer$EventListener;)V in class Lcom/google/android/exoplayer2/SimpleExoPlayer; or its super classes (declaration of ‘com.google.android.exoplayer2.SimpleExoPlayer’ appears in /data/app/App9.Android-1/base.apk)
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
at Java.Interop.JniEnvironment+InstanceMethods.CallVoidMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniMethodInfo method, Java.Interop.JniArgumentValue* args) [0x00069]