RelayServerData error with Matchmaking & Relay using PurrNet

[patent bough]

I have been struggling today and yesterday to add matchmaking and relay to my game. I'm using PurrNet for networking and my game worked with the Purr Transport to test things, but I now want to add actual matchmaking. For the user I want the matchmaking to be as simple as pressing the play button, then an opponent will be found, then they get connected together using client hosting through the Unity relay.

I have read a lot of documentation and forums, both from PurrNet and Unity, but I can't really find the code or solution I need. Sometimes I find something that looks useful, but then the tutorial ends, or it uses an outdated system. So I have been using AI a lot to figure stuff out, but AI is stupid and hallucinating things, and I can't check it's responses if I don't know what I'm doing.

I managed to make something kinda working, but I'm getting the error that I need to call SetRelayServerData() first, but I have no idea where to get the relayServerData from. No documentation talks about this. I looked through this and the readme on github, but I can't find any information.

After looking through the PurrNetNetworkHandler.cs code I found out it's already calling SetRelayServerData internally. And from the debug logs I can see that something is going wrong for the client because it says "Endpoint: invalid". But idk how to solve that.

Do I even need to get the relayServerData manually? Am I doing something else wrong? I have made this script following multiple random tutorials, AI and my own intuition, but at this point idk if I'm just doing something I'm not supposed to?

Here is the code I'm using:

async Task InitializeServices() {
    await UnityServices.InitializeAsync();

    if (!AuthenticationService.Instance.IsSignedIn) {
        await AuthenticationService.Instance.SignInAnonymouslyAsync();
    }

    Debug.Log("Signed in as: " + AuthenticationService.Instance.PlayerId);
}

public async void StartMatchmaking() {
    if (isMatchmaking) return;
    isMatchmaking = true;

    try {
        Unity.Services.Matchmaker.Models.Player player = new(AuthenticationService.Instance.PlayerId);

        List<Unity.Services.Matchmaker.Models.Player> players = new() { player };

        CreateTicketOptions options = new("default-queue") { };

        CreateTicketResponse ticket = await MatchmakerService.Instance.CreateTicketAsync(players, options);

        currentTicketId = ticket.Id;

        Debug.Log("Matchmaking started: " + ticket.Id);

        await PollTicket(ticket.Id);
    }
    catch (Exception e) {
        Debug.LogError("Matchmaking failed: " + e);
        isMatchmaking = false;
    }
}

private async Task PollTicket(string ticketId) {
    while (isMatchmaking) {
        await Task.Delay(1500);

        try {
            TicketStatusResponse ticketStatus = await MatchmakerService.Instance.GetTicketAsync(ticketId);
            if (ticketStatus == null) continue;

            MatchIdAssignment assignment = ticketStatus.Value as MatchIdAssignment;

            if (assignment.Status == MatchIdAssignment.StatusOptions.Found) {
                Debug.Log("Match ID Assignment found match!");
                isMatchmaking = false;
                await OnMatchFound(assignment.MatchId);
                return;
            }
            else if (assignment.Status == MatchIdAssignment.StatusOptions.InProgress) {
                Debug.Log("Match ID Assignment in progress...");
            }
            else if (assignment.Status == MatchIdAssignment.StatusOptions.Failed) {
                Debug.LogError("Failed to get ticket status. Error: " + assignment.Message);
                isMatchmaking = false;
            }
            else if (assignment.Status == MatchIdAssignment.StatusOptions.Timeout) {
                Debug.LogError("Failed to get ticket status. Ticket timed out.");
                isMatchmaking = false;
            }
            else {
                throw new InvalidOperationException();
            }
        }
        catch (Exception e) {
            Debug.LogError("Polling error: " + e);
            isMatchmaking = false;
            return;
        }
    }
}

private async Task OnMatchFound(string matchId) {
    try {
        var options = new SessionOptions {
            MaxPlayers = 2,
        }.WithPurrRelay();
       
        ISession session = await MultiplayerService.Instance.CreateOrJoinSessionAsync(matchId, options);

        //PurrnityTransport transport = NetworkManager.main.transport as PurrnityTransport;
        //var joinAllocation = await RelayService.Instance.JoinAllocationAsync(matchId);
        //var relayServerData = joinAllocation.ToRelayServerData("udp");
        //transport.SetRelayServerData(relayServerData);

        Debug.Log("Session acquired");

        if (session.IsHost) {
            Debug.Log("Session Starting HOST");
            //NetworkManager.main.StartHost();
        }
        else {
            Debug.Log("Session Starting CLIENT");
            //NetworkManager.main.StartClient();
        }
    }
    catch (Exception e) {
        Debug.LogError("Match flow failed: " + e);
    }
}

Here you can see some commented out things I tried, but nothing works.

I also tried doing matchmaking this way (idk why there is a different method to the other one, but I wanted to see if this worked) But this code gives the same error.

public async void TicketMatchmaking() {
    var matchmakerOptions = new MatchmakerOptions {
        QueueName = "default-queue"
    };

    var sessionOptions = new SessionOptions() {
        MaxPlayers = 2
    }.WithPurrRelay();

    var matchmakerCancellationSource = new CancellationTokenSource();

    ISession session = await MultiplayerService.Instance.MatchmakeSessionAsync(matchmakerOptions, sessionOptions, matchmakerCancellationSource.Token);
}

[raven bone]

All you need to do is use Sessions with this custom network handler
https://docs.unity.com/en-us/mps-sdk/manage-session-network-connection#example:-using-a-custom-network-handler

Here is how matchmaking will work
https://docs.unity.com/en-us/mps-sdk/matchmake-session

[patent bough]

Thanks for your reply @raven bone, but I think I already tried those right?
In that code snippet you can see I tried what is shown in this documentation, with ".WithPurrRelay();" for the custom network handler. But this also gives these same errors.

Oh what, I tried running the code again but get a different 504 error right now:

SessionException: (504) HTTP/1.1 504 Gateway Timeout
Unity.Services.Multiplayer.WrappedMultiplayerService.MatchmakeSessionAsync (Unity.Services.Multiplayer.MatchmakerOptions matchOptions, Unity.Services.Multiplayer.SessionOptions sessionOptions, System.Threading.CancellationToken cancellationToken) (at ./Library/PackageCache/com.unity.services.multiplayer@01ce6abde85b/Runtime/Multiplayer/WrappedMultiplayerService.cs:146)
SessionManager.CreateMatchmakingSession () (at Assets/Scripts/Networking/SessionManager.cs:53)
System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state) (at <1eb9db207454431c84a47bcd81e79c37>:0)
UnityEngine.UnitySynchronizationContext+WorkRequest.Invoke () (at <31f3cd5c2a074982a9d5664e7709cac1>:0)
UnityEngine.UnitySynchronizationContext.Exec () (at <31f3cd5c2a074982a9d5664e7709cac1>:0)
UnityEngine.UnitySynchronizationContext.ExecuteTasks () (at <31f3cd5c2a074982a9d5664e7709cac1>:0)

I get this by running this code:

public async void CreateMatchmakingSession() {
    var matchmakerOptions = new MatchmakerOptions {
        QueueName = "default-queue"
    };

    var sessionOptions = new SessionOptions() {
        MaxPlayers = 2
    }.WithPurrRelay();

    var matchmakerCancellationSource = new CancellationTokenSource();

    ISession session = await MultiplayerService.Instance.MatchmakeSessionAsync(matchmakerOptions, sessionOptions, matchmakerCancellationSource.Token);
}

[raven bone]

make sure you have matchmaking enabled in the unity cloud dashboatd. Also depends on what .WithPurrRelay() does. .WithNetworkHandler(new PurrNetNetworkHandler()) should work

[patent bough]

Matchmaking is enabled and I have created the queue and pool things.
I'm not sure what .WithPurrRelay() does, but I do that because all the documentation mentions it.

I also tried .WithNetworkHandler(new PurrNetNetworkHandler()); but that does not work. I get no errors, but the server does not even attempt to start.

[raven bone]

If you aren't seeing matchmaking ticket get created in the dashboard, then you might have to open a support ticket on that.

try testing without any firewalls enabled. that could be causing a timeout

[patent bough]

The ticket gets created and a match does get found, the problem somewhere with the starting of the connection. Let me send the full logs again for each method.

The logs for the MatchmakeSessionAsync code. (using .WithPurrRelay() again btw since that other suggestion didn't work)

And these are the logs for the ticket system with CreateOrJoinSessionAsync

[raven bone]

try a direct connection with WithPurrDirect()

[patent bough]

That kinda works for both without errors. But now I have the problem that the host only starts the server, and not server and client. So the game only has 1 client while it is supposed to have 2.

And I'm guessing you wanted me to try with direct instead or relay just to test right? Because you cant use direct in the live game right?

[raven bone]

Yea. just want to see if its an issue with how purrnet is handling the relay or not

[patent bough]

Do you know what else I could try?

[raven bone]

You could try another relay service. thought I saw that Purrnet has its own relay as well

[patent bough]

I used the Purr Transport with their relay address before trying to add this and that worked. But their server is for development only. And that system uses rooms, but I want to use a matchmaking system. Unity's system and things like authentication, friends, and the other UGS stuff looks so useful, so I would like to use that.

[raven bone]

sounds like its an issue with PurrNetNetworkHandler then

[patent bough]

I installed Unity's NGO and tried the script using that instead of PurrNet and it works! So I'm trying to switch to NGO now, but it does weird stuff, I'm trying to make a simple debug script that just shows ID's and stuff, but it only works on the host. How do I get this script to run locally for both clients?

using TMPro;
using Unity.Netcode;
using UnityEngine;

public class NetworkDebuggerNGO : NetworkBehaviour {

    public bool debugEnabled = true;

    [Header("UI Elements")]
    public TextMeshProUGUI statusText;

    private void Start() {
        if (!debugEnabled) return;
        Debug.Log("NetworkDebugger started. Waiting for OnSpawned...");
        statusText.text = "Waiting for network spawn...";
    }

    public override void OnNetworkSpawn() {
        Debug.Log($"OnSpawned called! My ID: {NetworkManager.LocalClientId}");
        if (!debugEnabled || !IsClient) return;

        NetworkManager.OnClientConnectedCallback += OnClientConnected;
        NetworkManager.OnClientDisconnectCallback += OnClientDisconnected;
        NetworkManager.OnClientStarted += OnClientStarted;
        NetworkManager.OnClientStopped += OnClientStopped;

        UpdateText();
    }

    public override void OnNetworkPreDespawn() {
        Debug.Log("OnNetworkPreDespawn called.");
        UpdateText();
    }

    public override void OnNetworkDespawn() {
        Debug.Log("OnNetworkDespawn called.");
        UpdateText();
    }

    // The 4 events call UpdateText

    private void UpdateText() {
        if (!statusText.gameObject.activeSelf) return;

        string text;
        text = $"My ID: {NetworkManager.LocalClientId}\n";
        text += $"Is Server: {IsServer}\n";
        text += $"Is Client: {IsClient}\n";
        text += $"Is Host: {IsHost}\n";
        text += "Connected Players:\n";

        foreach (NetworkClient player in NetworkManager.ConnectedClientsList) {
            text += $"{player.ClientId}, ";
        }

        statusText.text = text;
    }
}

[raven bone]

As long as the network object and this component are active it will run on the clients. Make sure nothing is disabled on the object in the scene

[patent bough]

The object just gets removed from the client's scene. While running it also gives this error on the client. See image 2 for the not running scene.

[raven bone]

if the object is getting destroyed that will cause issues. Try removing the network object and put it back

[patent bough]

I completely removed the old object and made a new one. It prompted me to add the Network Object and I clicked yes. I didn't change any settings on the Network Object (same as previous image) and then clicked play, but I got the same result.

[raven bone]

is this saved as a prefab? scene objects don't need to be one. See if the hash in the error is the same as the one in the scene

[patent bough]

It's just a normal object in the hierarchy, no prefab.

[raven bone]

Is the Global Object ID Has the same as in the error?

[patent bough]

Ill check after lunch

[patent bough]

Yes, weird that it's talking about prefabs while nothing is being spawned.

@raven bone btw the first image is the error from the client, the second image is from the host.

[raven bone]

Are you using Multiplayer Play Mode or a build for the client?

[patent bough]

Multiplayer play mode

[raven bone]

You might need to close the clone and reopen it. Sounds like the hashes are not matching for some reason

[patent bough]

I always close the clone after playing, so it's fresh each time. Also restarting Unity did nothing.

[raven bone]

Could be a bug if object hashes are not matching. Only other thing you can do is to delete the Libgrary folder in the project and reimport.

[patent bough]

I'll try.

[patent bough]

But they are matching right? The one in the inspector is the same as the log.

But imma try anyways

[raven bone]

the client is not finding the hash on its side for some reason

[patent bough]

I deleted the library folder and reloaded the project. I'm also getting this error each time I launch the project, but I dont think it has something to do with this.

You may not pass in objects that are already persistent
UnityEngine.StackTraceUtility:ExtractStackTrace ()
UnityEditorInternal.InternalEditorUtility:SaveToSerializedFileAndForgetInternal (string,UnityEngine.Object[],bool)
UnityEditorInternal.InternalEditorUtility:SaveToSerializedFileAndForget (UnityEngine.Object[],string,bool)
UnityEditor.ScriptableSingleton1<Unity.PlayMode.Editor.PlayModeUserSettings>:Save (bool) Unity.PlayMode.Editor.PlayModeUserSettings:set_LastActiveConfiguration (Unity.PlayMode.Editor.PlayModeConfiguration) Unity.PlayMode.Editor.PlayModeManager:AssignActiveConfig (Unity.PlayMode.Editor.PlayModeConfiguration) Unity.PlayMode.Editor.PlayModeManager:get_ActivePlayModeConfig () Unity.Multiplayer.PlayMode.Editor.ScenarioConfig:OnValidate () UnityEditorInternal.InternalEditorUtility:LoadSerializedFileAndForget (string) UnityEditor.ScriptableSingleton1<Unity.PlayMode.Editor.PlayModeUserSettings>:get_instance ()
Unity.PlayMode.Editor.PlayModeManager:get_ActivePlayModeConfig ()
Unity.PlayMode.Editor.PlaymodeDropdownButton:.ctor ()
Unity.PlayMode.Editor.PlayModeButtonsView:AddDropdownButton ()
Unity.PlayMode.Editor.PlayModeButtonsView:.ctor ()
Unity.PlayMode.Editor.PlayModeButtonsExtension:CreatePlayModeButtons (UnityEngine.UIElements.VisualElement)
UnityEditor.EditorApplication:Internal_CallDelayFunctions ()

I'll now test the thing again

Nope, still the same

[raven bone]

huh, it might actually. can you try making a build for the client and see if the same thing happens

[patent bough]

Sure, can I still run one of them in the editor?

[raven bone]

yea, if you can run the client in the editor so you can see what might be wrong there

[patent bough]

Ok, build is busy

[patent bough]

I made a build and it does the same thing. I tried like 10 times but the editor always becomes the host and the build the client.

[raven bone]

How are you starting and joining the match? You can make a button to start host/client

[patent bough]

I use matchmaking sessions.
ISession session = await MultiplayerService.Instance.CreateOrJoinSessionAsync(matchId, options);

and I also tried both
ISession session = await MultiplayerService.Instance.MatchmakeSessionAsync(matchmakerOptions, sessionOptions, matchmakerCancellationSource.Token);

But it's a development build so I can see the errors, and the are they same as the multiplayer play mode. Or did you want to see something other than the errors?

[raven bone]

we need to see what the object id hash is on the client and why it might be different

[patent bough]

Would I see that in the logs or somewhere else?

[raven bone]

You would need to see it in the inspector

one way is to run the client build as host and then use the editor as the client

[patent bough]

The thing is that the script is completely gone on the client, so you can't check the ID

I added a OnDestroy event to the script, and it does get triggered. Alsoo this time the main editor became the client.

private new void OnDestroy() {
    Debug.Log("Debugger destroyed!!");
}

And you can see they have the same ID before they get connected.

[raven bone]

Ok that is the issue then. Something is destroying that component in code.

[patent bough]

Well it's none of my code, it's just a simple NetworkBehaviour script with a few debug logs. Maybe it's NGO?

Or could the problem be I also have the PurrNet package in this same project? Nothing PurrNet related is in this scene tho.

[raven bone]

Ive never heard of that happening. But I've never used Purrnet either. If you remove the debugger script from that object, does it still get destroyed?

[patent bough]

I'll try that tomorrow or later tonight, gotta make dinner now.

[patent bough]

Before and after connecting

[raven bone]

Huh, You definitely have something destroying that object somewhere

It says that you have scene management disabled.

[patent bough]

Does that need to be on? I thought I should disable it because I don't need scene switches while networked, the entire multiplayer part is in 1 scene.

Ah I enabled it and now it works.

[raven bone]

unless you are doing custom scene management, you will want this on.

[patent bough]

Well I would manually change the scene to this scene when the game starts and transition to another scene when the game is over.

[raven bone]

it handles the in scene network object synchronization as well

with it disabled, you would need to make the debugger a network prefab

https://docs.unity3d.com/Packages/com.unity.netcode.gameobjects@2.10/manual/basics/scenemanagement/custom-management.html

[patent bough]

The thing is that I thought I didn't need scene object synchronization. In my head this script should work perfectly fine on it's own and does not need to be synchronized.