Multiplayer - Unable to rejoin a lobby

[whole acorn]

So I'm trying to make an online multiplayer game using Unity Netcode for GameObjects - Distributed Authority, and strangely enough I noticed that when a player leaves a lobby, then rejoins that same lobby, the error listed below* shows up. Some extra info, I got this working with unity's multiplayer packages, I'm running unity6.1, I'm quite new to game dev (less than a year), but moreso to online multiplayer, this is my first project.

When the initial host of a lobby tries to rejoin a lobby, they simply can't, but also don't get shown the start ui anymore where they can select another lobby. They just get stuck

When a non-host leaves the lobby and rejoins, the same error shows up, but this time the player is able to partially enter the lobby. They can be seen by other players, but their "disconnect" button is non-interactable, they don't show a code at the top and they can't chat. They also don't have a camera object in them yet still are able to look around which is incredibly weird.

This is an issue that seems to randomly have popped up as it didn't happen before. It's possible that I might have changed something, but I would have no clue as to what. I don't think changing code would be the best way to fix it, as this system used to work fine with rejoins before.. But I'm not experienced enough to be certain about that..

If anyone would be as kind as to point me in the right direction, I would be very, very grateful!
Thank you!

---

`ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.

Parameter name: index

System.Collections.Generic.List`1[T].get_Item (System.Int32 index) (at <d6e80b37d98246a5859a00c653f9fdf3>:0)

Unity.Multiplayer.Widgets.WidgetEventDispatcher.OnSessionJoined (Unity.Services.Multiplayer.ISession session, Unity.Multiplayer.Widgets.WidgetConfiguration widgetConfiguration) (at ./Library/PackageCache/com.unity.multiplayer.widgets@8f9a1d20b6e1/Runtime/Core/Base/Widget/WidgetEventDispatcher.cs:148)

Unity.Multiplayer.Widgets.SessionManager.set_ActiveSession (Unity.Services.Multiplayer.ISession value) (at ./Library/PackageCache/com.unity.multiplayer.widgets@8f9a1d20b6e1/Runtime/Session/Session/SessionManager.cs:35)

Unity.Multiplayer.Widgets.SessionManager.EnterSession (Unity.Multiplayer.Widgets.EnterSessionData enterSessionData) (at ./Library/PackageCache/com.unity.multiplayer.widgets@8f9a1d20b6e1/Runtime/Session/Session/SessionManager.cs:128)

Unity.Multiplayer.Widgets.EnterSessionBase.EnterSession () (at ./Library/PackageCache/com.unity.multiplayer.widgets@8f9a1d20b6e1/Runtime/Session/Widgets/Base/EnterSessionBase.cs:78)

System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state) (at <d6e80b37d98246a5859a00c653f9fdf3>:0)

UnityEngine.UnitySynchronizationContext+WorkRequest.Invoke () (at <2c271b216ff84328b73d1d7f2333e7ab>:0)

UnityEngine.UnitySynchronizationContext.Exec () (at <2c271b216ff84328b73d1d7f2333e7ab>:0)

UnityEngine.UnitySynchronizationContext.ExecuteTasks () (at <2c271b216ff84328b73d1d7f2333e7ab>:0)`

[crystal grove]

@whole acorn

You'll need to make something that resets NetCode Status when you leave.

(And btw, how do you got Unity as Discord presence?)

[whole acorn]

Thanks! I'll try that!

[crystal grove]

It should work

[whole acorn]

I manually set it in discord settings!

App activity tab

[crystal grove]

But it doesnt display Unity for me

Right now you can see Visual Studio on my activity but not Unity..

[whole acorn]

Well, if unity is opened, you should be able to select it to add it.. Normally that is

[crystal grove]

I will take a look at it

[crystal grove]

Do you get it?

Just a cleanup function to reset the Netcode status when a player leaves

[crystal grove]

@whole acorn Could you tell me when its fixed? So I can know if you need extra help

[whole acorn]

Hey thank you! I'm still trying to get it working currently. Especially with the protection levels of the package scripts

[crystal grove]

Just lmk if you need smth

Try to only use public methods

[whole acorn]

I'll try that. I'm currently trying to make another script to handle the resetting the netcode status by inheriting from Unity's multiplayer sessionmanager package script

[crystal grove]

internal → public and remove sealed basically

[whole acorn]

Yeah but I can't really modify anything in the package scripts.. I'd been advised that's bad business..

Thus I can't really modify the protection levels

Would it be a good practise to embed the whole multiplayer package so that I can safely make changes in it?

[crystal grove]

Yeah, thats possible but won't be able to get any more updates on the package..

[whole acorn]

Yeah I figured.. I don't see any other way to fix this issue though..

Because if I modify the package script's protection levels, the next time I boot up unity, it'll be undone again

[crystal grove]

You can try it.. , it depends on how you'll do it

[whole acorn]

So I discovered something new. The error is actually caused by another script I have that disables the widgets depending on whether or not the player is in a lobby.. But the issue is still partially there as if the lobby owner leaves the lobby and rejoins, they only get connected to the chat but don't actually get instantiated with a player prefab.. I also don't see any logs about ownership of the lobby being transfered to the next player.. Maybe that's why? I'm just theorizing here..

[crystal grove]

Does the host change to someone else when the original host leaves?

[whole acorn]

well, it's a distributed authority hosting system, so everyone is a host, but the ownership should transfer when the owner leaves, but I'm not seeing any proof that it does aside from that the lobby stays up after the owner leaves if there's 1 or more players still in it

[crystal grove]

check if the ownership gets transferred

[whole acorn]

I'm not quite sure how to do that

[crystal grove]

use LobbyService.Instance.GetLobbyAsync(lobbyId); then look for lobby.HostId

[whole acorn]

thanks, I'll try that

[crystal grove]

if lobby.HostId is the same then the ownership isn't transferred

[whole acorn]

Alright, finally got it working. Took me a while haha. So here's what I got.

When the host leaves, the ownership is not carried over to another player, because the game doesn't detect any other players in the lobby to carry over the ownership to..

So after the lobby owner leaves, there is no owner anymore

I'm now going to test and see what happens if an ordinary player attempts to join a lobby where the initial owner has left

Okay, so I found out that the ownership DOES actually get carried over, my bad. But once the initial owner leaves, nobody else can join that lobby(, or well.. Partially I'll explain). Even though ownership has been carried over to another player

When a player joins a lobby where the initial owner leaves from, they can use the chat system and others can see their messages, but they just don't get a player prefab which they can move and look around with

I have no clue where to go from here honestly..

[crystal grove]

@whole acorn Does it work perfectly now?

My bad for the late reponse.. was working.

[whole acorn]

Unfortunately not.. I was able to track down the cause as you can see above, but not quite find a solution..

[crystal grove]

Let me think.

Can you share me the code in a textfile?

[whole acorn]

which one specifically? Because there's alot of different scripts

[crystal grove]

Which one controls the Host ?

[whole acorn]

Still a lot. I'm using the unity multiplayer package

But I got the Session Manager, Network Manager.. Any of those?

[crystal grove]

Yeah, as long as I can take a look to fix it

[whole acorn]

Alright, thank you! Here's the two scripts. The SessionManager has been partially (and temporarily) modified for the debugs to figure out whether the ownership was being carried on

[crystal grove]

Of course it doesnt work lol

@whole acorn first of all: put AutoSpawnPlayerPrefabClientSide on true

[whole acorn]

I'm just glad to hear you know what's wrong haha

[whole acorn]

That one actually was already on, just through the unity editor

serializedfield

[crystal grove]

yeah but not in the script

OnFetchLocalPlayerPrefabToSpawn then AutoSpawnPlayerPrefabClientSide on true

[whole acorn]

does that matter?

I'll try it

[crystal grove]

I think it does wait

if it's not working you probably have to add a Distributed Authority script

[whole acorn]

How do I enable the AutoSpawnPlayerPrefabClientSide within the script? Probably a stupid question but I don't quite see a variable for it set to false

or do I make the variable myself and set it to true?

[crystal grove]

In Awake() add: NetworkManager.Singleton.NetworkConfig.AutoSpawnPlayerPrefabClientSide = true;

or just paste this one , i just edited it: void Awake() { if (NetworkManager.Singleton != null) { NetworkManager.Singleton.NetworkConfig.AutoSpawnPlayerPrefabClientSide = true; NetworkManager.Singleton.OnFetchLocalPlayerPrefabToSpawn = () => { return NetworkManager.Singleton.NetworkConfig.PlayerPrefab; }; } }

[whole acorn]

Thank you! I'll try that!

[crystal grove]

If its still not working , dont worry I will take a look tomarrow.

[whole acorn]

I cannot thank you enough man, seriously!

Alright so I tested it, unfortunately doesn't work yet, but I'ma keep trying some stuff, see if just maybe I'll get it to work. Thank you!

[crystal grove]

Its because actually I also had problems like these and its very frustating if you cant find it..

[crystal grove]

Can you add me into your Project or would that be too much??

[whole acorn]

Yeah it really is, I'm very thankful for your help!

[crystal grove]

No problem though. It will probably be fixed soon

[whole acorn]

No problem at all!

[crystal grove]

Like theres no way that its not possible

[whole acorn]

Exactly!

[crystal grove]

Theres just something wrong.

[whole acorn]

Through what service though?

[crystal grove]

I think theres a way.. wait , I have never done this before

[whole acorn]

Should I add you to the github repository?

[crystal grove]

Yeah

That would be better

[whole acorn]

Alright, wait is it okay if we continue talking in dm's?