Bug "Received error message from Relay: allocation ID client mismatch."

The error, "Received error message from Relay: allocation ID client mismatch.", appeared with no reference to the script it came from and without further explanation. It appears after I've started a host and the player prefab is instantiated with a somewhat random time after everything is set up. Although I found through Relay's Documentation what this means, I still have no idea how to fix it. Here is the definition: " ErrClientPlayerMismatch is returned when a client has sent a RELAY message to the server using an unknown network connection. It is intended to inform the client that the IP address they are using has changed from the one the Relay server is aware of. This error message indicates the client should re-bind with a new BIND message". I've been grappling with this issue for hours now and still cannot find the source of this issue. I am running Unity version 2021.3.15f1.

 

Yes I am using Netcode for GameObjects. You have the order correct and on the third step it takes a few seconds for the error message to pop up. I have also had other people run the game on their computers with the same error popping up.

 

1. Version 1.1.0
2. If you're talking about the 'Protocol Type' field in the Unity Transport Component, then it is set to Relay Unity Transport. Or are you talking about this?
3. Network communications continue but are slowed significantly and things like network client transforms are updated infrequently in comparison to when I did not receive this error.
4. The error continues to occur after changing 'Heartbeat Timeout Ms' to 0. I should also mention the error is printed more frequently to the console when changing this value to 0.

 

I see I never seem to have explicitly stated which protocol I was using in my code. In place of RelayServerData I have a struct called RelayHostData which has all the information from the allocation that is created but I don't have a field for the connection type. Here is a snippet of the code that creates the server allocation and feeds the transport the relay data:

Code (CSharp):

1. public async Task<RelayHostData> SetupRelay(){
2.         InitializationOptions options = new InitializationOptions()
3.         .SetEnvironmentName(environment);
4.  
5.         await UnityServices.InitializeAsync(options);
6.  
7.         if(!AuthenticationService.Instance.IsSignedIn){
8.             await AuthenticationService.Instance.SignInAnonymouslyAsync();
9.         }
10.  
11.        
12.         Allocation allocation = await Relay.Instance.CreateAllocationAsync(maxConnections);
13.  
14.         RelayHostData relayHostData = new RelayHostData
15.         {
16.             key = allocation.Key,
17.             Port = (ushort)allocation.RelayServer.Port,
18.             AllocationID = allocation.AllocationId,
19.             AllocationIDBytes = allocation.AllocationIdBytes,
20.             IPv4Address = allocation.RelayServer.IpV4,
21.             ConnectionData = allocation.ConnectionData
22.            
23.         };
24.        
25.         relayHostData.JoinCode = await Relay.Instance.GetJoinCodeAsync(relayHostData.AllocationID);
26.  
27.         Transport.SetRelayServerData(relayHostData.IPv4Address, relayHostData.Port, relayHostData.AllocationIDBytes, relayHostData.key, relayHostData.ConnectionData);
28.  
29.         Debug.Log($"Join code created: {relayHostData.JoinCode}");
30.         joinText.text = relayHostData.JoinCode;
31.        
32.  
33.         return relayHostData;
34.     }

Here is the RelayHostData struct as well:

Code (CSharp):

1. public struct RelayHostData{
2.     public string JoinCode;
3.     public string IPv4Address;
4.     public ushort Port;
5.     public Guid AllocationID;
6.     public byte[] AllocationIDBytes;
7.     public byte[] ConnectionData;
8.     public byte[] key;
9. }

 

Interesting...
I refactored my code to be more up to date with the documentation and have not seen the error appear. Most notably, I've changed the use of the "Relay" class to the "RelayService" class, got rid of my "RelayHostData" and "RelayJoinData" structs (I don't know why I made them, they were quite redundant) and replaced them with the "RelayServerData" struct instead, and I also set the connection type to "dtls" in the "RelayServerData" constructor. Despite these changes, I still don't know why this is too different from my previous code. Is there a difference between the "RelayService" and "Relay" classes? They both have the same functions needed to create and join allocations. Or was it because I switched the connection type to "dtls" instead of the default "udp"? Edit: I tried changing to the "udp" connection type and was not met with any errors.

 

Thanks for helping me on this issue. I was really pulling my hair out on this one, and thanks to you I better understand how netcode and relay work .