GamePlayActivity no field mUnityPlayer cause a AndroidJavaException crash

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[REQUIRED] Step 1: Describe your environment

• Unity version: 2021.3.23f1c1
• Google Mobile Ads Unity plugin version: v8.1.0 and v8.2.0
• Platform: Android (iOS, Android, Unity Editor)
• Platform OS version: Android 7 (eg iOS 10, Android 9)
• Any specific devices issue occurs on: all
• Mediation ad networks used, and their versions: no

[REQUIRED] Step 2: Describe the problem

1. java GamePlayActivity really no field “mUnityPlayer” in my case, mUnityPlayer is in other SDK.I use unity as a library;
2. Unity C# code, when call MobileAds.Initialize make the problem occur;

Steps to reproduce:

1. Yes. GamePlayActivity really no field “mUnityPlayer” in my case, mUnityPlayer is in other SDK.I use unity as a library.
2. Unity C# code, when call MobileAds.Initialize trigger;
3. UnityPlayer maybe can find by R.id.unitySurfaceView;

What happened? How can we make the problem occur? This could be a description, log/console output, etc.

E/Unity: AndroidJavaException: java.lang.NoSuchFieldError: no “Ljava/lang/Object;” field “mUnityPlayer” in class “Lio/wx/gp/play/ui/GamePlayActivity;” or its superclasses java.lang.NoSuchFieldError: no “Ljava/lang/Object;” field “mUnityPlayer” in class “Lio/wx/gp/play/ui/GamePlayActivity;” or its superclasses at com.unity3d.player.UnityPlayer.nativeRender(Native Method) at com.unity3d.player.UnityPlayer.access$800(Unknown Source) at com.unity3d.player.UnityPlayer$g$1.handleMessage(Unknown Source) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:203) at com.unity3d.player.UnityPlayer$g.run(Unknown Source) at UnityEngine.AndroidJNISafe.CheckException () [0x00000] in <00000000000000000000000000000000>:0 at UnityEngine.AndroidJNISafe.GetFieldID (System.IntPtr clazz, System.String name, System.String sig) [0x00000] in <00000000000000000000000000000000>:0 at UnityEngine._AndroidJNIHelper.GetFieldID (System.IntPtr jclass, System.String fieldName, System.St

Please share a downloadable sample project that reproduces the bug, if available. This greatly helps us to diagnose and fix the issue faster.

Relevant Code:

            List<String> deviceIds = new List<String>() { AdRequest.TestDeviceSimulator };
            // Configure TagForChildDirectedTreatment and test device IDs.
            RequestConfiguration requestConfiguration =
                new RequestConfiguration.Builder()
                .SetTagForChildDirectedTreatment(TagForChildDirectedTreatment.Unspecified)
                .SetTestDeviceIds(deviceIds).build();
            MobileAds.SetRequestConfiguration(requestConfiguration);
            // Initialize the Google Mobile Ads SDK.
            MobileAds.Initialize(HandleInitCompleteAction);

[guanghui1987]

Maybe I know the reason. Unity AndroidJavaObject.CallStatic maybe need to access mUnityPlayer. Unity AndroidJavaObject.Call maybe not need to access mUnityPlayer.

I do some testing in my case that is GamePlayActivity no field mUnityPlayer. and the results:

1. Unity 2021.3.6f1c1 google-ads-mobile-unity v8.1.0 v8.2.0 ok
2. Unity 2021.3.23f1c1 google-ads-mobile-unity v8.1.0 v8.2.0 not ok
3. Unity 2021.3.25f1c1 google-ads-mobile-unity v8.1.0 v8.2.0 not ok

public void Initialize(Action<IInitializationStatusClient> initCompleteAction)
{
	//IL_000c: Unknown result type (might be due to invalid IL or missing references)
	//IL_0012: Expected O, but got Unknown
	//IL_0023: Unknown result type (might be due to invalid IL or missing references)
	//IL_0029: Expected O, but got Unknown
	this.initCompleteAction = initCompleteAction;
	AndroidJavaClass val = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
	AndroidJavaObject @static = ((AndroidJavaObject)val).GetStatic<AndroidJavaObject>("currentActivity");
	AndroidJavaClass val2 = new AndroidJavaClass("com.google.android.gms.ads.MobileAds");
	((AndroidJavaObject)val2).CallStatic("initialize", new object[2] { @static, this });
}

[NVentimiglia]

@guanghui1987

I was unable to replicate this issue using 2021.3.25f1c1. I am not sure what is happening, but I would need to look at the project or additional logging to figure out what is happening. If you could, can you please open a support case on the on the help forum?