Unity AdMob実装後のエラー

UnityでAdMobを実装した直後に以下のようなエラーが出るようになりました。解決法をご教授いただけると幸いです。

A Native Collection has not been disposed, resulting in a memory leak. Allocated from:
Unity.Collections.NativeArray1:.ctor(Byte[], Allocator) UnityEngine.Networking.UploadHandlerRaw:.ctor(Byte[]) UnityEngine.Networking.UnityWebRequest:SetupPost(UnityWebRequest, WWWForm) UnityEngine.Networking.UnityWebRequest:Post(String, WWWForm) System.Reflection.MonoMethod:InternalInvoke(Object, Object[], Exception&) System.Reflection.MonoMethod:Invoke(Object, BindingFlags, Binder, Object[], CultureInfo) System.Reflection.MethodBase:Invoke(Object, Object[]) Google.PortableWebRequest:StartRequest(HttpMethod, String, IDictionary2, WWWForm) (at Z:\tmp\tmp.T7As57P2EG\third_party\unity\unity_jar_resolver\source\VersionHandlerImpl\src\PortableWebRequest.cs:481)
Google.<StartRequestOnMainThread>c__AnonStorey0:<>m__0() (at Z:\tmp\tmp.T7As57P2EG\third_party\unity\unity_jar_resolver\source\VersionHandlerImpl\src\PortableWebRequest.cs:443)
Google.RunOnMainThread:ExecuteNext() (at Z:\tmp\tmp.T7As57P2EG\third_party\unity\unity_jar_resolver\source\VersionHandlerImpl\src\RunOnMainThread.cs:486)
Google.RunOnMainThread:<ExecuteAllUnnested>m__1() (at Z:\tmp\tmp.T7As57P2EG\third_party\unity\unity_jar_resolver\source\VersionHandlerImpl\src\RunOnMainThread.cs:536)
Google.RunOnMainThread:RunAction(Action) (at Z:\tmp\tmp.T7As57P2EG\third_party\unity\unity_jar_resolver\source\VersionHandlerImpl\src\RunOnMainThread.cs:343)
Google.RunOnMainThread:ExecuteAllUnnested(Boolean) (at Z:\tmp\tmp.T7As57P2EG\third_party\unity\unity_jar_resolver\source\VersionHandlerImpl\src\RunOnMainThread.cs:530)
Google.RunOnMainThread:ExecuteAll() (at Z:\tmp\tmp.T7As57P2EG\third_party\unity\unity_jar_resolver\source\VersionHandlerImpl\src\RunOnMainThread.cs:512)
UnityEditor.EditorApplication:Internal_CallUpdateFunctions()