"Message was missing target player and target group" when group is set and player is joined to group

Amazon GameLift
, ,
#1

Hi all,

I’m walking through the frog tutorial for Unity and have client -> server messaging working, but server -> client messaging gives the following error in the server logs on the EC2 instance:

18 Nov 2020 09:09:55,193 [ERROR] (index.js) 371: Message was missing a target player and target group. Message: {“opCode”:777,“sender”:-1,“payload”:{“type”:“Buffer”,“data”:

I’m using the below function to send a “response” message from the server when the client sends a message:

function onMessage(gameMessage) {
const outMessage = session.newTextGameMessage(777,
session.getServerId(),
“A test message from the server”);
session.sendGroupMessage(outMessage, 0);
}

My understanding is I’m sending to group “0”. My client code should be registered to group “0” using the below code:

// Initiate a connection with the Realtime server with the given connection information
Client.Connect(endpoint, remoteTcpPort, listeningUdpPort, connectionToken);
Client.RequestGroupMembership(0);
Client.JoinGroup(0);

… so I’m at a complete loss as to why the error claims “missing target group”. I’m sure I’m missing something obvious - any help is much appreciated!

Thanks,
Chris

#2

I believe its because group 0 is special. Try using a positive group number

This is based on the comment here: https://docs.aws.amazon.com/gamelift/latest/developerguide/realtime-script.html

which says that group number should be positive. AFAIK -1 is all groups and >0 is specific groups. Not sure what group 0 is for.

#3

That was it! pounds head on desk You are awesome, thanks!

#4

I filed a documentation bug on the GameLift docs pages: https://docs.aws.amazon.com/gamelift/latest/developerguide/realtime-script.html

Will also reach out to the GameLift team to highlight your problem as maybe they can improve error messages returned in this case etc.