fix

Fixing the issue where users might try to start NetworkManager within OnClientStopped or OnServerStopped which would result in a failed start.

Author: NoelStephensUnity

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

@@ -1674,19 +1674,8 @@ internal void ShutdownInternal()
                 ConnectionManager.InvokeOnClientDisconnectCallback(LocalClientId);
             }
 
-            if (ConnectionManager.LocalClient.IsClient)
-            {
-                // If we were a client, we want to know if we were a host
-                // client or not. (why we pass in "IsServer")
-                OnClientStopped?.Invoke(ConnectionManager.LocalClient.IsServer);
-            }
-
-            if (ConnectionManager.LocalClient.IsServer)
-            {
-                // If we were a server, we want to know if we were a host
-                // or not. (why we pass in "IsClient")
-                OnServerStopped?.Invoke(ConnectionManager.LocalClient.IsClient);
-            }
+            // Save off the last local client settings
+            var localClient = ConnectionManager.LocalClient;
 
             // In the event shutdown is invoked within OnClientStopped or OnServerStopped, set it to false again
             m_ShuttingDown = false;
@@ -1706,6 +1695,21 @@ internal void ShutdownInternal()
             // can unsubscribe from tick updates and such.
             NetworkTimeSystem?.Shutdown();
             NetworkTickSystem = null;
+
+
+            if (localClient.IsClient)
+            {
+                // If we were a client, we want to know if we were a host
+                // client or not. (why we pass in "IsServer")
+                OnClientStopped?.Invoke(localClient.IsServer);
+            }
+
+            if (localClient.IsServer)
+            {
+                // If we were a server, we want to know if we were a host
+                // or not. (why we pass in "IsClient")
+                OnServerStopped?.Invoke(localClient.IsClient);
+            }
         }
 
         // Ensures that the NetworkManager is cleaned up before OnDestroy is run on NetworkObjects and NetworkBehaviours when quitting the application.

com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs

@@ -1269,7 +1269,7 @@ internal unsafe void UpdateNetworkObjectSceneChanges()
             foreach (var entry in NetworkObjectsToSynchronizeSceneChanges)
             {
                 // If it fails the first update then don't add for updates
-                if (!entry.Value.UpdateForSceneChanges())
+                if (entry.Value != null && !entry.Value.UpdateForSceneChanges())
                 {
                     CleanUpDisposedObjects.Push(entry.Key);
                 }