chore: Small separate updates

com.unity.netcode.gameobjects/Editor/NetworkBehaviourEditor.cs

@@ -326,14 +326,8 @@ private void OnEnable()
         /// </summary>
         /// <param name="transform">The current <see cref="Transform"/> we are inspecting for a parent</param>
         /// <returns>the root parent for the first <see cref="Transform"/> passed into the method</returns>
-        public static Transform GetRootParentTransform(Transform transform)
-        {
-            if (transform.parent == null || transform.parent == transform)
-            {
-                return transform;
-            }
-            return GetRootParentTransform(transform.parent);
-        }
+        [Obsolete("Use transform.root instead", true)]
+        public static Transform GetRootParentTransform(Transform transform) => transform.root;
 
         /// <summary>
         /// Used to determine if a GameObject has one or more NetworkBehaviours but
@@ -358,7 +352,7 @@ public static void CheckForNetworkObject(GameObject gameObject, bool networkObje
             }
 
             // Now get the root parent transform to the current GameObject (or itself)
-            var rootTransform = GetRootParentTransform(gameObject.transform);
+            var rootTransform = gameObject.transform.root;
             if (!rootTransform.TryGetComponent<NetworkManager>(out var networkManager))
             {
                 networkManager = rootTransform.GetComponentInChildren<NetworkManager>();

com.unity.netcode.gameobjects/Runtime/Core/NetworkBehaviour.cs

@@ -1,8 +1,10 @@
 #pragma warning disable IDE0005
 using System;
 using System.Collections.Generic;
-using System.Runtime.CompilerServices;
 using Unity.Collections;
+#if MULTIPLAYER_TOOLS && (DEVELOPMENT_BUILD || UNITY_EDITOR || UNITY_MP_TOOLS_NET_STATS_MONITOR_ENABLED_IN_RELEASE)
+using System.Runtime.CompilerServices;
+#endif
 using UnityEngine;
 #pragma warning restore IDE0005
 

com.unity.netcode.gameobjects/Runtime/Core/NetworkManager.cs

@@ -1010,10 +1010,10 @@ internal bool NetworkManagerCheckForParent(bool ignoreNetworkManagerCache = fals
 #if UNITY_EDITOR
             var isParented = NetworkManagerHelper.NotifyUserOfNestedNetworkManager(this, ignoreNetworkManagerCache);
 #else
-            var isParented = transform.root != transform;
+            var isParented = transform.parent != null;
             if (isParented)
             {
-                throw new Exception(GenerateNestedNetworkManagerMessage(transform));
+                Log.Error(new Context(LogLevel.Error, GenerateNestedNetworkManagerMessage(transform)));
             }
 #endif
             return isParented;
@@ -1029,7 +1029,17 @@ internal static string GenerateNestedNetworkManagerMessage(Transform transform)
         /// </summary>
         private void OnTransformParentChanged()
         {
+#if UNITY_EDITOR
+            // During editor playmode, we log the message as a dialog box
+            // and that script sets the parent back to root/null.
             NetworkManagerCheckForParent();
+#else
+            if (NetworkManagerCheckForParent())
+            {
+                // During runtime, we log the message and set our parent back to root/null.
+                transform.parent = null;
+            }
+#endif
         }
 
         /// <summary>

com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs

@@ -7,11 +7,7 @@
 using Unity.Netcode.Runtime;
 #if UNITY_EDITOR
 using UnityEditor;
-#if UNITY_2021_2_OR_NEWER
 using UnityEditor.SceneManagement;
-#else
-using UnityEditor.Experimental.SceneManagement;
-#endif
 #endif
 using UnityEngine;
 using UnityEngine.SceneManagement;
@@ -2665,7 +2661,7 @@ internal void InvokeBehaviourNetworkSpawn()
                 childBehaviour.InternalOnNetworkSpawn();
             }
 
-            // After initialization, we can then invoke OnNetworkSpawn on each child NetworkBehaviour.
+            // After internally spawning, we can then invoke OnNetworkSpawn on each child NetworkBehaviour.
             foreach (var childBehaviour in ChildNetworkBehaviours.Values)
             {
                 if (!childBehaviour.gameObject.activeInHierarchy)
@@ -2740,6 +2736,7 @@ internal string GenerateDisabledNetworkBehaviourWarning(NetworkBehaviour network
         }
 
         internal Dictionary<ushort, NetworkBehaviour> ChildNetworkBehaviours;
+
         internal bool InitializeChildNetworkBehaviours()
         {
             ChildNetworkBehaviours = new Dictionary<ushort, NetworkBehaviour>();
@@ -2770,9 +2767,7 @@ internal bool InitializeChildNetworkBehaviours()
                     networkTransform.IsNested = networkTransform.gameObject != gameObject;
                     NetworkTransforms.Add(networkTransform);
                 }
-
 #if COM_UNITY_MODULES_PHYSICS || COM_UNITY_MODULES_PHYSICS2D
-
                 var rigidbodyBase = behaviour as NetworkRigidbodyBase;
                 if (rigidbodyBase != null)
                 {
@@ -2914,18 +2909,18 @@ internal struct SerializedObject
             public ulong OwnerClientId;
             public ushort OwnershipFlags;
 
-            private const ushort k_IsPlayerObject = 0x001;
-            private const ushort k_HasParent = 0x002;
-            private const ushort k_IsSceneObject = 0x004;
-            private const ushort k_HasTransform = 0x008;
-            private const ushort k_IsLatestParentSet = 0x010;
-            private const ushort k_WorldPositionStays = 0x020;
-            private const ushort k_DestroyWithScene = 0x040;
-            private const ushort k_DontDestroyWithOwner = 0x080;
-            private const ushort k_HasOwnershipFlags = 0x100;
-            private const ushort k_SyncObservers = 0x200;
-            private const ushort k_SpawnWithObservers = 0x400;
-            private const ushort k_HasInstantiationData = 0x800;
+            private const ushort k_IsPlayerObject = 0x0001;
+            private const ushort k_HasParent = 0x0002;
+            private const ushort k_IsSceneObject = 0x0004;
+            private const ushort k_HasTransform = 0x0008;
+            private const ushort k_IsLatestParentSet = 0x0010;
+            private const ushort k_WorldPositionStays = 0x0020;
+            private const ushort k_DestroyWithScene = 0x0040;
+            private const ushort k_DontDestroyWithOwner = 0x0080;
+            private const ushort k_HasOwnershipFlags = 0x0100;
+            private const ushort k_SyncObservers = 0x0200;
+            private const ushort k_SpawnWithObservers = 0x0400;
+            private const ushort k_HasInstantiationData = 0x0800;
 
             public bool IsPlayerObject;
             public bool HasParent;

com.unity.netcode.gameobjects/Runtime/SceneManagement/SceneEventData.cs

@@ -1120,9 +1120,9 @@ internal void SynchronizeSceneNetworkObjects(NetworkManager networkManager)
                     }
                     var spawnedNetworkObject = NetworkObject.Deserialize(serializedObject, InternalBuffer, networkManager);
 
-                    var noStop = InternalBuffer.Position;
                     if (EnableSerializationLogs)
                     {
+                        var noStop = InternalBuffer.Position;
                         builder.AppendLine($"[Head: {noStart}][Tail: {noStop}][Size: {noStop - noStart}][{spawnedNetworkObject.name}][NID-{spawnedNetworkObject.NetworkObjectId}][Children: {spawnedNetworkObject.ChildNetworkBehaviours.Count}]");
                         LogArray(InternalBuffer.ToArray(), noStart, noStop, builder);
                     }

testproject/Assets/Tests/Manual/NestedNetworkTransforms/ChildMover.cs

@@ -45,20 +45,11 @@ public void PlayerIsMoving(float movementDirection)
             }
         }
 
-        private Transform GetRootParentTransform(Transform transform)
-        {
-            if (transform.parent != null)
-            {
-                return GetRootParentTransform(transform.parent);
-            }
-            return transform;
-        }
-
         protected override void OnNetworkPostSpawn()
         {
             if (CanCommitToTransform)
             {
-                m_RootParentTransform = GetRootParentTransform(transform);
+                m_RootParentTransform = transform.root;
                 if (RandomizeScale)
                 {
                     transform.localScale = transform.localScale * Random.Range(0.5f, 1.5f);