Network Variable Serialisaton Of FixedStrings

[MertKalkanci]

Description

Cannot Sync NetworkVariable<FixedString64Bytes>

I just updated my Projects Unity version to 2022.3.42f1 LTS from 2022.3.12f1

Everything works fine except FixedString synchronisation. Following code was working fine on Netcode 1.6.0 but now not working on 1.10.0

When I create a Network Variable by:

[HideInInspector] public NetworkVariable<FixedString64Bytes> playerNickname;

private void Awake()
 {
playerNickname = new NetworkVariable<FixedString64Bytes>(new FixedString64Bytes("Nameless Jelly"), NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);
}

or

[HideInInspector] public NetworkVariable<FixedString64Bytes> playerNickname = new NetworkVariable<FixedString64Bytes>(new FixedString64Bytes("Nameless Jelly"), NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);

and when I change its value I get following errors:

NullReferenceException: Object reference not set to an instance of an object
Unity.Netcode.FixedStringSerializer`1[T].WriteDelta (Unity.Netcode.FastBufferWriter writer, T& value, T& previousValue) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/NetworkVariable/NetworkVariableSerialization.cs:701)
Unity.Netcode.NetworkVariableSerialization`1[T].WriteDelta (Unity.Netcode.FastBufferWriter writer, T& value, T& previousValue) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/NetworkVariable/NetworkVariableSerialization.cs:1642)
Unity.Netcode.NetworkVariable`1[T].WriteDelta (Unity.Netcode.FastBufferWriter writer) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/NetworkVariable/NetworkVariable.cs:199)
Unity.Netcode.NetworkVariableDeltaMessage.Serialize (Unity.Netcode.FastBufferWriter writer, System.Int32 targetVersion) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Messaging/Messages/NetworkVariableDeltaMessage.cs:99)
Unity.Netcode.NetworkMessageManager.SendMessage[TMessageType,TClientIdListType] (TMessageType& message, Unity.Netcode.NetworkDelivery delivery, TClientIdListType& clientIds) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Messaging/NetworkMessageManager.cs:641)
Unity.Netcode.NetworkMessageManager.SendMessage[T] (T& message, Unity.Netcode.NetworkDelivery delivery, System.UInt64 clientId) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Messaging/NetworkMessageManager.cs:814)
Unity.Netcode.NetworkConnectionManager.SendMessage[T] (T& message, Unity.Netcode.NetworkDelivery delivery, System.UInt64 clientId) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Connection/NetworkConnectionManager.cs:1297)
Unity.Netcode.NetworkBehaviour.NetworkVariableUpdate (System.UInt64 targetClientId, System.Int32 behaviourIndex) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviour.cs:1004)
Unity.Netcode.NetworkBehaviour.VariableUpdate (System.UInt64 targetClientId) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviour.cs:950)
Unity.Netcode.NetworkBehaviourUpdater.NetworkBehaviourUpdate () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviourUpdater.cs:76)
Unity.Netcode.NetworkBehaviourUpdater.NetworkBehaviourUpdater_Tick () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviourUpdater.cs:129)
Unity.Netcode.NetworkTickSystem.UpdateTick (System.Double localTimeSec, System.Double serverTimeSec) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Timing/NetworkTickSystem.cs:102)
Unity.Netcode.NetworkTimeSystem.UpdateTime () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Timing/NetworkTimeSystem.cs:141)
Unity.Netcode.NetworkManager.NetworkUpdate (Unity.Netcode.NetworkUpdateStage updateStage) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkManager.cs:57)
Unity.Netcode.NetworkUpdateLoop.RunNetworkUpdateStage (Unity.Netcode.NetworkUpdateStage updateStage) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkUpdateLoop.cs:192)
Unity.Netcode.NetworkUpdateLoop+NetworkPreUpdate+<>c.<CreateLoopSystem>b__0_0 () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkUpdateLoop.cs:239)

Reproduce Steps

Of course I know the part of the code I've sent in the bottom is not a good idea but whenever I update the value by doing playerNickname.Value = new FixedString64Bytes("SOMESTRING"); I get the errors I've given

        [HideInInspector] public NetworkVariable<FixedString64Bytes> playerNickname = new NetworkVariable<FixedString64Bytes>(new FixedString64Bytes("Nameless Jelly"), NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);

        public override void OnNetworkSpawn()
        {
            base.OnNetworkSpawn();

            if (IsOwner)
            {
                StartCoroutine(GetPlayerNick());
            }
        }

        private IEnumerator GetPlayerNick()
        {
            yield return new WaitForSeconds(0.5f);
            string nick = "Nameless Jelly";

            if (PlayerPrefs.HasKey("Nick"))
                nick = PlayerPrefs.GetString("Nick");
            Debug.Log("Setting nickname to " + nick);
            playerNickname.Value = new FixedString64Bytes(nick);
        }

Actual Outcome

Those errors:

NullReferenceException: Object reference not set to an instance of an object
Unity.Netcode.FixedStringSerializer`1[T].WriteDelta (Unity.Netcode.FastBufferWriter writer, T& value, T& previousValue) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/NetworkVariable/NetworkVariableSerialization.cs:701)
Unity.Netcode.NetworkVariableSerialization`1[T].WriteDelta (Unity.Netcode.FastBufferWriter writer, T& value, T& previousValue) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/NetworkVariable/NetworkVariableSerialization.cs:1642)
Unity.Netcode.NetworkVariable`1[T].WriteDelta (Unity.Netcode.FastBufferWriter writer) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/NetworkVariable/NetworkVariable.cs:199)
Unity.Netcode.NetworkVariableDeltaMessage.Serialize (Unity.Netcode.FastBufferWriter writer, System.Int32 targetVersion) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Messaging/Messages/NetworkVariableDeltaMessage.cs:99)
Unity.Netcode.NetworkMessageManager.SendMessage[TMessageType,TClientIdListType] (TMessageType& message, Unity.Netcode.NetworkDelivery delivery, TClientIdListType& clientIds) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Messaging/NetworkMessageManager.cs:641)
Unity.Netcode.NetworkMessageManager.SendMessage[T] (T& message, Unity.Netcode.NetworkDelivery delivery, System.UInt64 clientId) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Messaging/NetworkMessageManager.cs:814)
Unity.Netcode.NetworkConnectionManager.SendMessage[T] (T& message, Unity.Netcode.NetworkDelivery delivery, System.UInt64 clientId) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Connection/NetworkConnectionManager.cs:1297)
Unity.Netcode.NetworkBehaviour.NetworkVariableUpdate (System.UInt64 targetClientId, System.Int32 behaviourIndex) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviour.cs:1004)
Unity.Netcode.NetworkBehaviour.VariableUpdate (System.UInt64 targetClientId) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviour.cs:950)
Unity.Netcode.NetworkBehaviourUpdater.NetworkBehaviourUpdate () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviourUpdater.cs:76)
Unity.Netcode.NetworkBehaviourUpdater.NetworkBehaviourUpdater_Tick () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkBehaviourUpdater.cs:129)
Unity.Netcode.NetworkTickSystem.UpdateTick (System.Double localTimeSec, System.Double serverTimeSec) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Timing/NetworkTickSystem.cs:102)
Unity.Netcode.NetworkTimeSystem.UpdateTime () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Timing/NetworkTimeSystem.cs:141)
Unity.Netcode.NetworkManager.NetworkUpdate (Unity.Netcode.NetworkUpdateStage updateStage) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkManager.cs:57)
Unity.Netcode.NetworkUpdateLoop.RunNetworkUpdateStage (Unity.Netcode.NetworkUpdateStage updateStage) (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkUpdateLoop.cs:192)
Unity.Netcode.NetworkUpdateLoop+NetworkPreUpdate+<>c.<CreateLoopSystem>b__0_0 () (at ./Library/PackageCache/com.unity.netcode.gameobjects@1.10.0/Runtime/Core/NetworkUpdateLoop.cs:239)

And when I get value of playerNickname I just get the default value I initialised it with.

Expected Outcome

After I do playerNickname.Value = new FixedString64Bytes("SOMESTRING"); I expect change of that string value.

Screenshots

Just to show timing of errors:

Environment

• OS: Ubuntu 24.04 LTS (x86_64) & Nvidia Driver Version: 550.90.07
• Unity Version: 2022.3.42f1 LTS
• Netcode Version: 1.10.0

[MertKalkanci]

We apologize for any confusion this might have caused. We are aware that this PR does not resolve the issue and have an alternate approach that will be reviewed early next week. If it gets a sign off on the different approach, then I will start a patch update to NGO v1.10.1 that will include the alternate fix.

If you are having this issue and using fixed strings, then you could update your manifest with this: "com.unity.netcode.gameobjects": "https://github.com/Unity-Technologies/com.unity.netcode.gameobjects.git?path=com.unity.netcode.gameobjects#fix/fixedstring-byte-writing-and-comparing",

And report back here if that resolves your issue.
#2953 (comment)

After reading that, I've updated package manifest.json to:
"com.unity.netcode.gameobjects": "https://github.com/Unity-Technologies/com.unity.netcode.gameobjects.git?path=com.unity.netcode.gameobjects#develop",
and issue is fixed, waiting for next release to change back to unity registry sources.

[TCGXR]

Any news on this?

[MertKalkanci]

This issue fixed on version 1.11.0, you can upgrade your netcode version via updating package manifest.json file
with changing "com.unity.netcode.gameobjects": "1.10.0", into "com.unity.netcode.gameobjects": "1.11.0", and updating package in unity editor