diff --git a/CHANGELOG.md b/CHANGELOG.md
index 057879987d..ab0c642d88 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@
 - The GDK now depends on .NET Core v3.1.3xx instead of v2.2.2xx. [#1443](https://github.com/spatialos/gdk-for-unity/pull/1443)
 - Removed APIs for AuthorityLossImminent. [#1451](https://github.com/spatialos/gdk-for-unity/pull/1451)
   - All authority changes to `AuthorityLossImminent` will now be dropped, and callbacks will no longer trigger.
+- Removed the `AuthoritativeEntityResolver`. The implementation was fundamentally flawed. [#1453](https://github.com/spatialos/gdk-for-unity/pull/1453)
 
 ### Added
 
diff --git a/UPGRADE_GUIDE.md b/UPGRADE_GUIDE.md
index 39d21b39dd..728eef0052 100644
--- a/UPGRADE_GUIDE.md
+++ b/UPGRADE_GUIDE.md
@@ -25,10 +25,26 @@ The `Reader` and `Writer` classes have had their `public Authority Authority` pr
 
 ### .NET Core Update
 
-The GDK, in particular the code generator and deployment launcher, has been updated to use [.NET Core SDK v3.1.3xx](https://dotnet.microsoft.com/download/dotnet-core/3.1). 
+The GDK, in particular the code generator and deployment launcher, has been updated to use [.NET Core SDK v3.1.3xx](https://dotnet.microsoft.com/download/dotnet-core/3.1).
 
 To update, download and install the new version from the link provided above.
 
+### `AuthoritativeEntityResolver` removal
+
+We removed the `AuthoritativeEntityResolver` as the implementation was fundamentally flawed. Depending on how you were using it, there are different replacements:
+
+#### For your player entity
+
+Use the `OwningWorkerEntityResolver` which uses the `OwningWorker` component from the Player Lifecycle Feature Module. Make sure that when you create your player's `EntityTemplate` you add the relevant components with:
+
+```csharp
+PlayerLifecycleHelper.AddPlayerLifecycleComponents(EntityTemplate template, clientWorkerId, serverAccess);
+```
+
+#### For server authoritative entities
+
+If you were using this resolver on the server, we recommend merging the two Prefabs into one and rely on the GDK enabling/disabling behaviours when they are active or not.
+
 ## From `0.3.7` to `0.3.8`
 
 ### Asset based entity representation
@@ -69,7 +85,7 @@ The Scripting Backend defined in the Unity Project Settings is now overwritten b
 
 In [#1376](https://github.com/spatialos/gdk-for-unity/pull/1376), some generated code has changed locations in your project. If you are ignoring these files in your `.gitignore`, you will want to add two new entries:
 
-Before: 
+Before:
 
 ```
 Assets/Generated/Source.meta
diff --git a/workers/unity/Packages/io.improbable.gdk.core/Representation/Types/AuthoritativeEntityResolver.cs b/workers/unity/Packages/io.improbable.gdk.core/Representation/Types/AuthoritativeEntityResolver.cs
deleted file mode 100644
index 9e9067ab84..0000000000
--- a/workers/unity/Packages/io.improbable.gdk.core/Representation/Types/AuthoritativeEntityResolver.cs
+++ /dev/null
@@ -1,37 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using Unity.Entities;
-using UnityEngine;
-
-namespace Improbable.Gdk.Core.Representation.Types
-{
-    [Serializable]
-    public class AuthoritativeEntityResolver : IEntityRepresentationResolver
-    {
-        public string EntityType => entityType;
-        public IEnumerable<uint> RequiredComponents => requiredComponents.Append(authComponentId);
-
-#pragma warning disable 649
-        [SerializeField] private string entityType;
-        [SerializeField] private GameObject ownedPrefab;
-        [SerializeField] private GameObject unownedPrefab;
-        [SerializeField] private uint authComponentId;
-        [SerializeField] private uint[] requiredComponents = { };
-#pragma warning restore 649
-
-        public GameObject Resolve(SpatialOSEntityInfo entityInfo, EntityManager manager)
-        {
-            var authComponent = ComponentDatabase.GetMetaclass(authComponentId).Authority;
-            return manager.HasComponent(entityInfo.Entity, authComponent)
-                ? ownedPrefab
-                : unownedPrefab;
-        }
-
-        public void DeclareReferencedPrefabs(List<GameObject> referencedPrefabs)
-        {
-            referencedPrefabs.Add(ownedPrefab);
-            referencedPrefabs.Add(unownedPrefab);
-        }
-    }
-}
diff --git a/workers/unity/Packages/io.improbable.gdk.core/Representation/Types/AuthoritativeEntityResolver.cs.meta b/workers/unity/Packages/io.improbable.gdk.core/Representation/Types/AuthoritativeEntityResolver.cs.meta
deleted file mode 100644
index 24a47b0421..0000000000
--- a/workers/unity/Packages/io.improbable.gdk.core/Representation/Types/AuthoritativeEntityResolver.cs.meta
+++ /dev/null
@@ -1,3 +0,0 @@
-fileFormatVersion: 2
-guid: 87830c8d74314007815a7ec480991479
-timeCreated: 1590577562
\ No newline at end of file