joinRoomReturn/createRoomReturn not called when there is an error

Hi @indie_d.

joinRoomReturn() gets called with an according error response just fine for me if the room does not exist.
You can quickly verify this in demo_loadBalancing by changing the line to mLoadBalancingClient.opJoinRandomRoom(); inside NetworkLogic::opJoinRandomRoom() into mLoadBalancingClient.opJoinRoom(L"test"); and setting a breakpoint inside NetworkLogic::joinRoomReturn().

That createRoomReturn() does not get called when the client already is inside a room, is intended behavior, as in this case the client already knows that the operation won't succeed on the server, so it does not even attempt to send it and immediately returns false. Callbacks by design only get called when the operation request returns true.