NullReferenceException on instance of script

Unity Engine
1

I’m making a multiplayer game using Lidgren and I am fairly new to unity. I have a couple of scripts that I need to communicate with one another through scenes, one of which is a server which can’t be repeatedly made as I need the server to stay constant throughout the scenes. In script A, the server, there is a method to send a message to all clients that requires some parameters and I added this in order to allow other scripts to access the method.

public static NetworkServer Instance { get; private set; }

public static void SendMessage(string text, NetDeliveryMethod deliveryMethod)
    {
        NetOutgoingMessage sendMsg = Instance.server.CreateMessage();
        sendMsg.Write(text);
        Instance.server.SendToAll(sendMsg, deliveryMethod);
    }

The second script, in a different scene calls it like this:

public void SendColourMatchMessage()
    {
        NetworkServer.SendMessage("CMStart", NetDeliveryMethod.ReliableOrdered);
    }

The communication between scripts appears to work through debugging, but the line:

NetOutgoingMessage sendMsg = Instance.server.CreateMessage();

throws a NullReferenceException:
NullReferenceException: Object reference not set to an instance of an object
NetworkServer.SendMessage (System.String text, Lidgren.Network.NetDeliveryMethod deliveryMethod) (at Assets/NetworkServer.cs:82)

I’m assuming this means there is no instance of the script, but I don’t exactly understand this and would appreciate any help.

2

Where do you set the value of “Instance” ?

3

I don’t think it’s referenced anywhere else apart from the aforementioned code, what would I set it to?

4

Hopefully you understand variables.

It’s of type NetworkServer, so it should be set to that. You didn’t post more of the script, but chances are you’re trying to create a singleton, so it needs to be set to to itself if it’s on the NetworkServer script.

1 Like
5

Ah yes, this fixed it. Thanks

Instance = this;