Object reference not set to an instance of an object

[Miguel_Arregui]

I am having a problem at the moment of spawning a building. Everything works fine until the moment the building shouls spawn, instead of spawning this mesage apears

NullReferenceException: Object reference not set to an instance of an object
BuildingButton.PlaceBuilding () (at Assets/_Game/_Scripsts/Buildings/BuildingButton.cs:83)

In that line es the player.CmdTryPlaceBuilding and for some reason it has a null reference. If I just comment that line there is no errors. Is I debug the get id and the hit point they apear on the console so the problem should be on the player but I can not find the error. Also I already check a thousand times in Unity and everything in the editor is as in the lecture.

This is my player script

[SerializeField] private Building[] buildings = new Building[0];

    private List<Villager> myUnits = new List<Villager>();
    private List<Building> myBuildings = new List<Building>();
    

    public List<Villager> GetMyUnits()
    {
        return myUnits;
    }

    public List<Building> GetMyBuilings()
    {
        return myBuildings;
    }

    #region Server

    public override void OnStartServer()
    {
        Villager.ServerOnUnitSpawned += ServerHangleUnitSpawned;
        Villager.ServerOnUnitDespawned += ServerHangleUnitDespawned;

        Building.ServerOnBuildingSpawned += ServerHangleBuildingSpawned;
        Building.ServerOnBuildingDespawned += ServerHangleBuildingDespawned;
    }

    public override void OnStopServer()
    {
        Villager.ServerOnUnitSpawned -= ServerHangleUnitSpawned;
        Villager.ServerOnUnitDespawned -= ServerHangleUnitDespawned;

        Building.ServerOnBuildingSpawned -= ServerHangleBuildingSpawned;
        Building.ServerOnBuildingDespawned -= ServerHangleBuildingDespawned;
    }

    [Command]
    public void CmdTryPlaceBuilding(int buildingID, Vector3 buildingLocation)
    {
        Building buildingToPlace = null;

        foreach (Building building in buildings)
        {
            if (building.GetId() == buildingID)
            {
                buildingToPlace = building;
                break;
            }
        }

        if (buildingToPlace == null) { return; }

        GameObject buildingInstace =
            Instantiate(buildingToPlace.gameObject, buildingLocation, buildingToPlace.transform.rotation);

        NetworkServer.Spawn(buildingInstace, connectionToClient);
    }
    private void ServerHangleUnitSpawned(Villager unit)
    {
        if(unit.connectionToClient.connectionId != connectionToClient.connectionId) { return; }
        myUnits.Add(unit);
    }
    private void ServerHangleUnitDespawned(Villager unit)
    {
        if (unit.connectionToClient.connectionId != connectionToClient.connectionId) { return; }
        myUnits.Remove(unit);
    }

    private void ServerHangleBuildingSpawned(Building building)
    {
        if (building.connectionToClient.connectionId != connectionToClient.connectionId) { return; }
        myBuildings.Add(building);
    }
    private void ServerHangleBuildingDespawned(Building building)
    {
        if (building.connectionToClient.connectionId != connectionToClient.connectionId) { return; }
        myBuildings.Remove(building);
    }
    #endregion

    #region Client

    public override void OnStartAuthority()
    {
        if (NetworkServer.active) { return; }

        Villager.AuthorityOnUnitSpawned += AuthorityHangleUnitSpawned;
        Villager.AuthorityOnUnitDespawned += AuthorityHangleUnitDespawned;

        Building.AuthorityOnBuildingSpawned += AuthorityHangleBuildingSpawned;
        Building.AuthorityOnBuildingDespawned += AuthorityHangleBuildingDespawned;
    }

    public override void OnStopClient()
    {
        if (!isClientOnly || !isOwned) { return; }

        Villager.AuthorityOnUnitSpawned -= AuthorityHangleUnitSpawned;
        Villager.AuthorityOnUnitDespawned -= AuthorityHangleUnitDespawned;

        Building.AuthorityOnBuildingSpawned -= AuthorityHangleBuildingSpawned;
        Building.AuthorityOnBuildingDespawned -= AuthorityHangleBuildingDespawned;

    }

    private void AuthorityHangleUnitSpawned(Villager unit)
    {
        myUnits.Add(unit);
    }
    private void AuthorityHangleUnitDespawned(Villager unit)
    {
        myUnits.Remove(unit);
    }

    private void AuthorityHangleBuildingSpawned(Building building)
    {
        myBuildings.Add(building);
    }
    private void AuthorityHangleBuildingDespawned(Building building)
    {
        myBuildings.Remove(building);
    }

    #endregion

type or paste code here

[bixarrio]

The error is in BuildingButton.cs, not your player script. if player.CmdTryPlaceBuilding() is the only thing on that line, then it’s very likely that player is null.

[Miguel_Arregui]

Thanks! the problem was that I missed the

    if (player == null)
    {
        player = NetworkClient.connection.identity.GetComponent<NetworkPlayer>();
    }