chore: remove unwanted network object exceptions (#3867)

* Replace exceptions by logging and return.
* Update log levels and types.

* NotListeningException marked obsolete .
* Fix `NetworkObjectParentingTests` test:
- use Expect LogType.Error instead of LogType.Exception.

* Keep `OverflowExceptions`:
- when serialize is out of buffer space.
- for deserialization buffer issue.

* Styling and cleanup + replaced SceneObject by NetworkObject in log.

* Add `DuplicateHideShowTest`.
* Fix: `NetworkShow` behavior when it is called twice.

* Changelog update.

Author: noellie-velez

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -20,18 +20,19 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 
 ### Removed
-
+- Removed un-needed exceptions on `NetworkObject.cs`. (#3867)
 
 ### Fixed
 
 - Fixed issue where an attachable could log an error upon being de-spawned during shutdown. (#3895)
 - NestedNetworkVariables initialized with no value no longer throw an error. (#3891)
+- Fixed `NetworkShow` behavior when it is called twice. (#3867)
 
 ### Security
 
 
 ### Obsolete
-
+- `NotListeningException` is now marked as obsolete as it is no longer used internally. (#3867)
 
 ## [2.10.0] - 2026-03-01
 

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

@@ -1458,7 +1458,10 @@ internal NetworkSceneHandle GetSceneOriginHandle()
         {
             if (SceneOriginHandle.IsEmpty() && IsSpawned && IsSceneObject != false)
             {
-                throw new Exception($"{nameof(GetSceneOriginHandle)} called when {nameof(SceneOriginHandle)} is still zero but the {nameof(NetworkObject)} is already spawned!");
+                if (NetworkManager.LogLevel <= LogLevel.Error)
+                {
+                    NetworkLog.LogErrorServer($"{nameof(GetSceneOriginHandle)} called when {nameof(SceneOriginHandle)} is still zero but the {nameof(NetworkObject)} is already spawned!");
+                }
             }
             return !SceneOriginHandle.IsEmpty() ? SceneOriginHandle : gameObject.scene.handle;
         }
@@ -1481,32 +1484,40 @@ public void NetworkShow(ulong clientId)
         {
             if (!IsSpawned)
             {
-                throw new SpawnStateException("Object is not spawned");
+                if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                {
+                    NetworkLog.LogErrorServer($"[{name}] Attempted NetworkShow while {nameof(NetworkObject)} not spawned.");
+                }
+                return;
             }
 
             if (!HasAuthority)
             {
                 if (NetworkManagerOwner.DistributedAuthorityMode)
                 {
-                    throw new NotServerException($"Only the owner-authority can change visibility when distributed authority mode is enabled!");
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogError($"[{name}] Only the owner-authority can change visibility when distributed authority mode is enabled!");
+                    }
+                    return;
                 }
                 else
                 {
-                    throw new NotServerException("Only the authority can change visibility");
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogError($"[{name}] Only the server can change visibility!");
+                    }
+                    return;
                 }
             }
 
             if (Observers.Contains(clientId))
             {
-                if (NetworkManagerOwner.DistributedAuthorityMode)
-                {
-                    Debug.LogError($"The object {name} is already visible to Client-{clientId}!");
-                    return;
-                }
-                else
+                if (NetworkManagerOwner.LogLevel <= LogLevel.Developer)
                 {
-                    throw new NotServerException("Only server can change visibility");
+                    NetworkLog.LogWarning($"[{name}] {nameof(NetworkObject)} is already visible to Client-{clientId}! (ignoring)");
                 }
+                return;
             }
 
             if (CheckObjectVisibility != null && !CheckObjectVisibility(clientId))
@@ -1556,8 +1567,8 @@ public static void NetworkShow(List<NetworkObject> networkObjects, ulong clientI
         /// <remarks>
         /// Usage: Use to stop sending updates to the targeted client, "netcode invisible", for a currently visible <see cref="NetworkObject"/>.<br />
         /// <br />
-        /// Dynamically Spawned: <see cref="NetworkObject"/>s will be despawned and destroyed on the targeted client's side.<br />
-        /// In-Scene Placed: <see cref="NetworkObject"/>s will only be despawned on the targeted client's side.<br />
+        /// Dynamically Spawned: <see cref="NetworkObject"/>s will be de-spawned and destroyed on the targeted client's side.<br />
+        /// In-Scene Placed: <see cref="NetworkObject"/>s will only be de-spawned on the targeted client's side.<br />
         /// <br />
         /// See Also:<br />
         /// <see cref="NetworkHide(List{NetworkObject}, ulong)"/><br />
@@ -1568,18 +1579,30 @@ public void NetworkHide(ulong clientId)
         {
             if (!IsSpawned)
             {
-                throw new SpawnStateException("Object is not spawned");
+                if (NetworkManager.LogLevel <= LogLevel.Error)
+                {
+                    NetworkLog.LogErrorServer($"[{name}] Attempted NetworkHide while {nameof(NetworkObject)} is not spawned.");
+                }
+                return;
             }
 
-            if (!HasAuthority && !NetworkManagerOwner.DAHost)
+            if (!HasAuthority)
             {
                 if (NetworkManagerOwner.DistributedAuthorityMode)
                 {
-                    throw new NotServerException($"Only the owner-authority can change visibility when distributed authority mode is enabled!");
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogError($"[{name}] Only the owner-authority can change visibility when distributed authority mode is enabled!");
+                    }
+                    return;
                 }
                 else
                 {
-                    throw new NotServerException("Only the authority can change visibility");
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogError($"[{name}] Only the server can change visibility!");
+                    }
+                    return;
                 }
             }
 
@@ -1589,9 +1612,9 @@ public void NetworkHide(ulong clientId)
                 {
                     if (NetworkManagerOwner.LogLevel <= LogLevel.Developer)
                     {
-                        Debug.LogWarning($"{name} is already hidden from Client-{clientId}! (ignoring)");
-                        return;
+                        NetworkLog.LogWarning($"[{name}] {nameof(NetworkObject)} already hidden from Client-{clientId}! (ignoring)");
                     }
+                    return;
                 }
                 Observers.Remove(clientId);
 
@@ -1724,18 +1747,30 @@ internal void SpawnInternal(bool destroyWithScene, ulong ownerClientId, bool pla
 
             if (!NetworkManagerOwner.IsListening)
             {
-                throw new NotListeningException($"{nameof(NetworkManagerOwner)} is not listening, start a server or host before spawning objects");
+                if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                {
+                    NetworkLog.LogError($"[{name}] {nameof(NetworkManagerOwner)} is not listening, start a server or host before spawning objects.");
+                }
+                return;
             }
 
             if ((!NetworkManagerOwner.IsServer && !NetworkManagerOwner.DistributedAuthorityMode) || (NetworkManagerOwner.DistributedAuthorityMode && !NetworkManagerOwner.LocalClient.IsSessionOwner && NetworkManagerOwner.LocalClientId != ownerClientId))
             {
                 if (NetworkManagerOwner.DistributedAuthorityMode)
                 {
-                    throw new NotServerException($"When distributed authority mode is enabled, you can only spawn NetworkObjects that belong to the local instance! Local instance id {NetworkManagerOwner.LocalClientId} is not the same as the assigned owner id: {ownerClientId}!");
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogError($"[{name}] When distributed authority mode is enabled, you can only spawn NetworkObjects that belong to the local instance! Local instance id {NetworkManagerOwner.LocalClientId} is not the same as the assigned owner id: {ownerClientId}!");
+                    }
+                    return;
                 }
                 else
                 {
-                    throw new NotServerException($"Only server can spawn {nameof(NetworkObject)}s");
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogError($"[{name}] Only server can spawn {nameof(NetworkObject)}s.");
+                    }
+                    return;
                 }
             }
 
@@ -2256,7 +2291,10 @@ private void OnTransformParentChanged()
                     return;
                 }
                 transform.parent = m_CachedParent;
-                Debug.LogException(new NotListeningException($"[{name}] {nameof(networkManager)} is not listening, start a server or host before re-parenting"));
+                if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                {
+                    NetworkLog.LogError($"[{name}] {nameof(networkManager)} is not listening, start a server or host before re-parenting.");
+                }
                 return;
             }
 
@@ -2273,7 +2311,10 @@ private void OnTransformParentChanged()
                 else
                 {
                     transform.parent = m_CachedParent;
-                    Debug.LogException(new SpawnStateException($"[{name}] {nameof(NetworkObject)} can only be re-parented after being spawned"));
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogErrorServer($"[{name}] {nameof(NetworkObject)} can only be re-parented after being spawned!");
+                    }
                 }
                 return;
             }
@@ -2293,7 +2334,7 @@ private void OnTransformParentChanged()
                     }
                     else
                     {
-                        Debug.LogException(new NotServerException($"[{name}] Only the server can re-parent {nameof(NetworkObject)}s"));
+                        NetworkLog.LogError($"[{name}] Only the server can re-parent {nameof(NetworkObject)}s.");
                     }
                 }
                 return;
@@ -2307,14 +2348,20 @@ private void OnTransformParentChanged()
                 {
                     transform.parent = m_CachedParent;
                     AuthorityAppliedParenting = false;
-                    Debug.LogException(new InvalidParentException($"[{name}] Invalid parenting, {nameof(NetworkObject)} moved under a non-{nameof(NetworkObject)} parent"));
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogErrorServer($"[{name}] Invalid parenting, {nameof(NetworkObject)} moved under a non-{nameof(NetworkObject)} parent");
+                    }
                     return;
                 }
                 else if (!parentObject.IsSpawned)
                 {
                     transform.parent = m_CachedParent;
                     AuthorityAppliedParenting = false;
-                    Debug.LogException(new SpawnStateException($"[{name}] {nameof(NetworkObject)} can only be re-parented under another spawned {nameof(NetworkObject)}"));
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Error)
+                    {
+                        NetworkLog.LogErrorServer($"[{name}] {nameof(NetworkObject)} can only be re-parented under another spawned {nameof(NetworkObject)}.");
+                    }
                     return;
                 }
 
@@ -2536,7 +2583,10 @@ internal void InvokeBehaviourNetworkSpawn()
             {
                 if (!childBehaviour.gameObject.activeInHierarchy)
                 {
-                    Debug.LogWarning($"{GenerateDisabledNetworkBehaviourWarning(childBehaviour)}");
+                    if (NetworkManagerOwner.LogLevel <= LogLevel.Developer)
+                    {
+                        NetworkLog.LogWarning($"{GenerateDisabledNetworkBehaviourWarning(childBehaviour)}");
+                    }
                     continue;
                 }
                 childBehaviour.InternalOnNetworkSpawn();
@@ -3327,7 +3377,11 @@ internal static NetworkObject Deserialize(in SerializedObject serializedObject,
             // Spawn the NetworkObject
             if (networkObject.IsSpawned)
             {
-                throw new SpawnStateException($"[{networkObject.name}] Object-{networkObject.NetworkObjectId} is already spawned!");
+                if (NetworkManager.Singleton.LogLevel <= LogLevel.Error)
+                {
+                    NetworkLog.LogErrorServer($"[{networkObject.name}] Object-{networkObject.NetworkObjectId} is already spawned!");
+                }
+                return null;
             }
 
             // Invoke the non-authority local spawn method

com.unity.netcode.gameobjects/Runtime/Exceptions/NotListeningException.cs

@@ -5,6 +5,7 @@ namespace Unity.Netcode
     /// <summary>
     /// Exception thrown when the operation require NetworkManager to be listening.
     /// </summary>
+    [Obsolete("Not used anymore.")]
     public class NotListeningException : Exception
     {
         /// <summary>

com.unity.netcode.gameobjects/Tests/Runtime/NetworkShowHideTests.cs

@@ -892,5 +892,32 @@ public IEnumerator NetworkShowAndChangeOwnership()
             AssertOnTimeout($"Timed out waiting for clients-{m_NewOwner.LocalClientId} to gain ownership of object {m_OwnershipNetworkObject.NetworkObjectId}!");
             VerboseDebug($"Client {m_NewOwner.LocalClientId} now owns object {m_OwnershipNetworkObject.NetworkObjectId}!");
         }
+
+        [UnityTest]
+        public IEnumerator DuplicateHideShowTest()
+        {
+            var authority = GetAuthorityNetworkManager();
+            var nonAuthority = GetNonAuthorityNetworkManager();
+            m_ClientId0 = nonAuthority.LocalClientId;
+            ShowHideObject.ClientTargetedNetworkObjects.Clear();
+            ShowHideObject.ClientIdToTarget = m_ClientId0;
+            ShowHideObject.Silent = true;
+
+            var spawnedObject1 = SpawnObject(m_PrefabToSpawn, authority);
+            m_NetSpawnedObject1 = spawnedObject1.GetComponent<NetworkObject>();
+
+            m_NetSpawnedObject1.GetComponent<ShowHideObject>().MyNetworkVariable.Value++;
+            m_NetSpawnedObject1.NetworkHide(m_ClientId0);
+            m_NetSpawnedObject1.NetworkHide(m_ClientId0);
+
+            yield return WaitForConditionOrTimeOut(() => !nonAuthority.SpawnManager.SpawnedObjects.ContainsKey(m_NetSpawnedObject1.NetworkObjectId));
+            AssertOnTimeout($"NetworkObject {m_NetSpawnedObject1.name} is still spawned on client-{nonAuthority.LocalClientId} after timeout!");
+
+            m_NetSpawnedObject1.NetworkShow(m_ClientId0);
+            m_NetSpawnedObject1.NetworkShow(m_ClientId0);
+
+            yield return WaitForConditionOrTimeOut(() => nonAuthority.SpawnManager.SpawnedObjects.ContainsKey(m_NetSpawnedObject1.NetworkObjectId));
+            AssertOnTimeout($"NetworkObject {m_NetSpawnedObject1.name} is not yet spawned on client-{nonAuthority.LocalClientId} after timeout!");
+        }
     }
 }

testproject/Assets/Tests/Runtime/ObjectParenting/NetworkObjectParentingTests.cs

@@ -207,7 +207,7 @@ public void SetupSet(Transform rootTransform, int setIndex, NetworkManager netwo
             Assert.That(m_Pickup_NetObjs[setIndex], Is.Not.Null);
             Assert.That(m_Pickup_Back_NetObjs[setIndex], Is.Not.Null);
 
-            LogAssert.Expect(LogType.Exception, new Regex("start a server or host", RegexOptions.IgnoreCase));
+            LogAssert.Expect(LogType.Error, new Regex("start a server or host", RegexOptions.IgnoreCase));
             var cachedParent = m_Cube_NetObjs[setIndex].parent;
             m_Cube_NetObjs[setIndex].parent = m_Pickup_NetObjs[setIndex];
             Assert.That(m_Cube_NetObjs[setIndex].parent, Is.EqualTo(cachedParent), $"Transform {m_Cube_NetObjs[setIndex].parent.name} is not equal to transform {cachedParent.name}");