null exception when spawning | Official Unity Discord | Page 1

lime escarp Feb 16, 2025, 9:53 PM

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Which object is coming up as null?

empty pike Feb 16, 2025, 10:07 PM

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im not sure... The error shows up from a unity networking script when I press the button to spawn

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the button itself has a network object component tho:

cloud knoll Feb 16, 2025, 10:35 PM

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empty pike im not sure... The error shows up from a unity networking script when I press th...

Post the entire error

empty pike Feb 16, 2025, 10:36 PM

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Unity.Netcode.NetworkMetrics.GetObjectIdentifier (Unity.Netcode.NetworkObject networkObject) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Metrics/NetworkMetrics.cs:527)
Unity.Netcode.NetworkMetrics.TrackRpcSent (System.UInt64 receiverClientId, Unity.Netcode.NetworkObject networkObject, System.String rpcName, System.String networkBehaviourName, System.Int64 bytesCount) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Metrics/NetworkMetrics.cs:342)
Unity.Netcode.LocalSendRpcTarget.Send (Unity.Netcode.NetworkBehaviour behaviour, Unity.Netcode.RpcMessage& message, Unity.Netcode.NetworkDelivery delivery, Unity.Netcode.RpcParams rpcParams) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Messaging/RpcTargets/LocalSendRpcTarget.cs:52)
Unity.Netcode.ServerRpcTarget.Send (Unity.Netcode.NetworkBehaviour behaviour, Unity.Netcode.RpcMessage& message, Unity.Netcode.NetworkDelivery delivery, Unity.Netcode.RpcParams rpcParams) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Messaging/RpcTargets/ServerRpcTarget.cs:86)
Unity.Netcode.NetworkBehaviour.__endSendRpc (Unity.Netcode.FastBufferWriter& bufferWriter, System.UInt32 rpcMethodId, Unity.Netcode.RpcParams rpcParams, Unity.Netcode.RpcAttribute+RpcAttributeParams attributeParams, Unity.Netcode.SendTo defaultTarget, Unity.Netcode.RpcDelivery rpcDelivery) (at ./Library/PackageCache/com.unity.netcode.gameobjects/Runtime/Core/NetworkBehaviour.cs:399)
PlayerController.SpawnFireballRPC (System.Single x, System.Single y) (at Assets/PlayerController.cs:62)
PlayerController.Fireball () (at Assets/PlayerController.cs:56)
UnityEngine.Events.InvokableCall.Invoke () (at <44f3679c53d1477a9c6e72f269e3a3a9>:0)
UnityEngine.Events.UnityEvent.Invoke () (at <44f3679c53d1477a9c6e72f269e3a3a9>:0)
UnityEngine.UI.Button.Press () (at ./Library/PackageCache/com.unity.ugui/Runtime/UGUI/UI/Core/Button.cs:70)
UnityEngine.UI.Button.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) (at ./Library/PackageCache/com.unity.ugui/Runtime/UGUI/UI/Core/Button.cs:114)
UnityEngine.EventSystems.ExecuteEvents.Execute (UnityEngine.EventSystems.IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at ./Library/PackageCache/com.unity.ugui/Runtime/UGUI/EventSystem/ExecuteEvents.cs:57)
UnityEngine.EventSystems.ExecuteEvents.Execute[T] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.ExecuteEvents+EventFunction`1[T1] functor) (at ./Library/PackageCache/com.unity.ugui/Runtime/UGUI/EventSystem/ExecuteEvents.cs:272)
UnityEngine.EventSystems.EventSystem:Update() (at ./Library/PackageCache/com.unity.ugui/Runtime/UGUI/EventSystem/EventSystem.cs:530)

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did I set the RPC wrong ?

cloud knoll Feb 16, 2025, 10:39 PM

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is the fireballPrefab in the spawnable objects list?

empty pike Feb 16, 2025, 10:39 PM

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yes

cloud knoll Feb 16, 2025, 10:40 PM

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Are you destroying anything on the player object after it's spawned?

empty pike Feb 16, 2025, 10:41 PM

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no

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ohh hold up, I have a script from the docs that I copy pasted that makes it not server authorative...

using Unity.Netcode.Components;

[DisallowMultipleComponent] // Prevents you from adding the ClientNetworkTransform to the object more than once.
public class ClientNetworkTransform : NetworkTransform
{
    /// <summary>
    /// Used to determine who can write to this playerTransform. Owner client only.
    /// This imposes state to the server. This is putting trust on your clients. Make sure no security-sensitive features use this playerTransform.
    /// </summary>
    protected override bool OnIsServerAuthoritative()
    {
        return false;
    }
}

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im changing the rpc to send to clientandhost instead

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maybe thatll do something

cloud knoll Feb 16, 2025, 10:44 PM

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That won't work

empty pike Feb 16, 2025, 10:45 PM

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ur right lol

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it shouldnt be sendtoserver anyway tho right? Since the topology is clienthosted, and I have that script from the unity docs to make it so im assuming. The host would act as the server, would send to server = send to host in this instance ?

cloud knoll Feb 16, 2025, 11:04 PM

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Host = Client + Server

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There’s nothing wrong with your spawning code. You would get different errors for that

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I’ve never seen the error you’re getting, there’s something else that you must be doing that’s off

lime escarp Feb 16, 2025, 11:38 PM

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empty pike the button itself has a network object component tho:

The button should not be networked

empty pike Feb 17, 2025, 12:22 AM

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i was thinking it'd be weird to have every button be networked since that just seems inneficient. But I was following a code monkey tutorial and they mentioned with RPCs u want the object to have a network object component, the derived from NetworkBehaviour in the script, and the RPC header thing, I thought that first part he mentioned might have been something I needed to do for the button since its from the Event onclick

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i didnt add it at first, it was just a troubleshooting thing i added afterward just in case

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but its still not working :C

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This is the playerprefab's inspector, is there something im missing from the network object and transform components ?

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fireball prefab

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ive tried the 2 different authoirty modes, owner and server but no luck

lime escarp Feb 17, 2025, 2:28 AM

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empty pike i was thinking it'd be weird to have every button be networked since that just s...

be sure to remove the network object from the button. How is the button referencing the player object?

empty pike Feb 17, 2025, 2:48 AM

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through the prefabs player controller script, calls Fireball() which itself calls the fireballRPC with the given x, and y

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and network object from the button removed 🫡

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thats the structure code monkey used anyway in his example. Player's script calls a function that calls an RPC. Although his was an on mouse click event and mines a button click.

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im assuming I cant directly put the RPC on the button click, but i doubt thats the issue anyway

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alright I added some debugs, apparently the RPC is being called from something without ownership ?

public void Fireball()
{
    if (fireballPrebab == null)
    {
        Debug.LogError("Fireball prefab is not assigned!");
        return;
    }

    if (!IsOwner)
    {
        Debug.LogError("FireballRPC() called from a non-owner player!");
        return;
    }
    SpawnFireballRPC(finalPosition.x, finalPosition.y);
}```

lime escarp Feb 17, 2025, 3:28 AM

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empty pike

How are you assigning this in the inspector when the player is not in the scene yet?

empty pike Feb 17, 2025, 3:30 AM

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... is this one of those "u cant do this with a prefab " things owo

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i dragged the prefab of the player into it from the assets folder , I can't do that ?

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ig this is where the GameManager comes into play

lime escarp Feb 17, 2025, 4:02 AM

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empty pike ... is this one of those "u cant do this with a prefab " things owo

The button has no way of knowing which player prefab it's for.

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You need to assign the button listener in code when the local player spawns in

empty pike Feb 17, 2025, 4:10 AM

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thinksmart

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she's alive !

#null exception when spawning