Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.Activity.runOnUiThread(java.lang.Runnable)' on a null object reference at net.gree.unitywebview.CWebViewPlugin.<init>(CWebViewPlugin.java:122)

Hi,
We are using this plugin for both android and iOS. We got this below issue from Firebase Console after we upload it. Kindly provide us the solution ASAP.
I got a lot of errors like this

Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.Activity.runOnUiThread(java.lang.Runnable)' on a null object reference
at net.gree.unitywebview.CWebViewPlugin.(CWebViewPlugin.java:122)
at java.lang.Class.newInstance(Class.java)
at android.app.Fragment.instantiate(Fragment.java:627)
at android.app.FragmentState.instantiate(Fragment.java:114)
at android.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1880)
at android.app.FragmentController.restoreAllState(FragmentController.java:123)
at android.app.Activity.onCreate(Activity.java:1048)
at com.unity3d.player.UnityPlayerActivity.onCreate()
at com.google.firebase.MessagingUnityPlayerActivity.onCreate(MessagingUnityPlayerActivity.java:75)
at android.app.Activity.performCreate(Activity.java:6904)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1136)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3266)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3415)
at android.app.ActivityThread.access$1100(ActivityThread.java:229)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1821)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:7325)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

Can you help us fix this problem

Start at CWebViewPlugin.java:122 and trace how the plugin is instantiated during Android Activity restoration, using the reported stack trace as the entry point. Check how the Activity reference is initialized before runOnUiThread is called. Done means the reported startup path no longer produces this NullPointerException, with a regression check if the project provides one.