Error while compiling StackSizeController: 'IFuelSystem' does not contain a definition for 'GetFuelItem' and no accessible extension method 'GetFuelItem' accepting a first argument of type 'IFuelSystem' could be found (are you missing a using directive or an assembly reference?) | Line: 285, Pos: 53

Try this.

Replace 

private void OnEntitySpawned(Minicopter heli)
{
    // Ignore if a known plugin is loaded that adjusts heli fuel.
    if (AirFuel != null || GetToDaChoppa != null || VehicleVendorOptions != null)
        return;

    // Must delay for vendor-spawned helis since the creatorEntity is set after spawn.
    NextTick(() =>
    {
        if (heli == null
            // Make sure it's a vendor-spawned heli.
            || !heli.IsSafe()
            // Make sure the game hasn't changed unexpectedly.
            || heli.StartingFuelUnits() != -1)
            return;

        // Try-catch block to handle unexpected errors
        try
        {
            // Get the fuel system and check if it's a StorageContainer
            var fuelSystem = heli.GetFuelSystem() as StorageContainer;
            if (fuelSystem == null)
                return;

            // Iterate through the items in the container to find the fuel item
            Item fuelItem = null;
            foreach (var item in fuelSystem.inventory.itemList)
            {
                if (item.info.shortname == "lowgradefuel")
                {
                    fuelItem = item;
                    break;
                }
            }

            if (fuelItem == null
                // Ignore other types of fuel since they will have been placed by mods.
                || fuelItem.info.shortname != "lowgradefuel"
                // Ignore if the fuel amount is unexpected, since a mod likely adjusted it.
                || fuelItem.amount != fuelItem.info.stackable / 5)
                return;

            var hookResult = Interface.CallHook("OnVendorHeliFuelAdjust", heli);
            if (hookResult is bool && (bool)hookResult == false)
                return;

            fuelItem.amount = 100;
            fuelItem.MarkDirty();
        }
        catch (Exception ex)
        {
            // Log the error message
            Puts($"Error adjusting fuel for heli: {ex.Message}");
        }
    });
}
​

private void OnEntitySpawned(Minicopter heli)
{
    // Ignore if a known plugin is loaded that adjusts heli fuel.
    if (AirFuel != null || GetToDaChoppa != null || VehicleVendorOptions != null)
        return;

    // Must delay for vendor-spawned helis since the creatorEntity is set after spawn.
    NextTick(() =>
    {
        if (heli == null
            // Make sure it's a vendor-spawned heli.
            || !heli.IsSafe()
            // Make sure the game hasn't changed unexpectedly.
            || heli.StartingFuelUnits() != -1)
            return;

        // Try-catch block to handle unexpected errors
        try
        {
            // Get the fuel system and check if it's a StorageContainer
            var fuelSystem = heli.GetFuelSystem() as StorageContainer;
            if (fuelSystem == null)
                return;

            // Iterate through the items in the container to find the fuel item
            Item fuelItem = null;
            foreach (var item in fuelSystem.inventory.itemList)
            {
                if (item.info.shortname == "lowgradefuel")
                {
                    fuelItem = item;
                    break;
                }
            }

            if (fuelItem == null
                // Ignore other types of fuel since they will have been placed by mods.
                || fuelItem.info.shortname != "lowgradefuel"
                // Ignore if the fuel amount is unexpected, since a mod likely adjusted it.
                || fuelItem.amount != fuelItem.info.stackable / 5)
                return;

            var hookResult = Interface.CallHook("OnVendorHeliFuelAdjust", heli);
            if (hookResult is bool && (bool)hookResult == false)
                return;

            fuelItem.amount = 100;
            fuelItem.MarkDirty();
        }
        catch (Exception ex)
        {
            // Log the error message
            Puts($"Error adjusting fuel for heli: {ex.Message}");
        }
    });
}
​

bonjour j ai le meme probleme

Oops, I accidentally posted the same two blocks of code

replace

private void OnEntitySpawned(Minicopter heli)
{
    // Ignore if a known plugin is loaded that adjusts heli fuel.
    if (AirFuel != null || GetToDaChoppa != null || VehicleVendorOptions != null)
        return;

    // Must delay for vendor-spawned helis since the creatorEntity is set after spawn.
    NextTick(() =>
    {
        if (heli == null
            // Make sure it's a vendor-spawned heli.
            || !heli.IsSafe()
            // Make sure the game hasn't changed unexpectedly.
            || heli.StartingFuelUnits() != -1)
            return;

        var fuelItem = (heli.GetFuelSystem() as EntityFuelSystem)?.GetFuelItem();
        if (fuelItem == null
            // Ignore other types of fuel since they will have been placed by mods.
            || fuelItem.info.shortname != "lowgradefuel"
            // Ignore if the fuel amount is unexpected, since a mod likely adjusted it.
            || fuelItem.amount != fuelItem.info.stackable / 5)
            return;

        var hookResult = Interface.CallHook("OnVendorHeliFuelAdjust", heli);
        if (hookResult is bool && (bool)hookResult == false)
            return;

        fuelItem.amount = 100;
        fuelItem.MarkDirty();
    });
}
​

with

private void OnEntitySpawned(Minicopter heli)
{
    // Ignore if a known plugin is loaded that adjusts heli fuel.
    if (AirFuel != null || GetToDaChoppa != null || VehicleVendorOptions != null)
        return;

    // Must delay for vendor-spawned helis since the creatorEntity is set after spawn.
    NextTick(() =>
    {
        if (heli == null
            // Make sure it's a vendor-spawned heli.
            || !heli.IsSafe()
            // Make sure the game hasn't changed unexpectedly.
            || heli.StartingFuelUnits() != -1)
            return;

        // Try-catch block to handle unexpected errors
        try
        {
            // Get the fuel system and check if it's a StorageContainer
            var fuelSystem = heli.GetFuelSystem() as StorageContainer;
            if (fuelSystem == null)
                return;

            // Iterate through the items in the container to find the fuel item
            Item fuelItem = null;
            foreach (var item in fuelSystem.inventory.itemList)
            {
                if (item.info.shortname == "lowgradefuel")
                {
                    fuelItem = item;
                    break;
                }
            }

            if (fuelItem == null
                // Ignore other types of fuel since they will have been placed by mods.
                || fuelItem.info.shortname != "lowgradefuel"
                // Ignore if the fuel amount is unexpected, since a mod likely adjusted it.
                || fuelItem.amount != fuelItem.info.stackable / 5)
                return;

            var hookResult = Interface.CallHook("OnVendorHeliFuelAdjust", heli);
            if (hookResult is bool && (bool)hookResult == false)
                return;

            fuelItem.amount = 100;
            fuelItem.MarkDirty();
        }
        catch (Exception ex)
        {
            // Log the error message
            Puts($"Error adjusting fuel for heli: {ex.Message}");
        }
    });
}

LordGunga

Oops, I accidentally posted the same two blocks of code

replace

private void OnEntitySpawned(Minicopter heli)
{
    // Ignore if a known plugin is loaded that adjusts heli fuel.
    if (AirFuel != null || GetToDaChoppa != null || VehicleVendorOptions != null)
        return;

    // Must delay for vendor-spawned helis since the creatorEntity is set after spawn.
    NextTick(() =>
    {
        if (heli == null
            // Make sure it's a vendor-spawned heli.
            || !heli.IsSafe()
            // Make sure the game hasn't changed unexpectedly.
            || heli.StartingFuelUnits() != -1)
            return;

        var fuelItem = (heli.GetFuelSystem() as EntityFuelSystem)?.GetFuelItem();
        if (fuelItem == null
            // Ignore other types of fuel since they will have been placed by mods.
            || fuelItem.info.shortname != "lowgradefuel"
            // Ignore if the fuel amount is unexpected, since a mod likely adjusted it.
            || fuelItem.amount != fuelItem.info.stackable / 5)
            return;

        var hookResult = Interface.CallHook("OnVendorHeliFuelAdjust", heli);
        if (hookResult is bool && (bool)hookResult == false)
            return;

        fuelItem.amount = 100;
        fuelItem.MarkDirty();
    });
}
​

with

private void OnEntitySpawned(Minicopter heli)
{
    // Ignore if a known plugin is loaded that adjusts heli fuel.
    if (AirFuel != null || GetToDaChoppa != null || VehicleVendorOptions != null)
        return;

    // Must delay for vendor-spawned helis since the creatorEntity is set after spawn.
    NextTick(() =>
    {
        if (heli == null
            // Make sure it's a vendor-spawned heli.
            || !heli.IsSafe()
            // Make sure the game hasn't changed unexpectedly.
            || heli.StartingFuelUnits() != -1)
            return;

        // Try-catch block to handle unexpected errors
        try
        {
            // Get the fuel system and check if it's a StorageContainer
            var fuelSystem = heli.GetFuelSystem() as StorageContainer;
            if (fuelSystem == null)
                return;

            // Iterate through the items in the container to find the fuel item
            Item fuelItem = null;
            foreach (var item in fuelSystem.inventory.itemList)
            {
                if (item.info.shortname == "lowgradefuel")
                {
                    fuelItem = item;
                    break;
                }
            }

            if (fuelItem == null
                // Ignore other types of fuel since they will have been placed by mods.
                || fuelItem.info.shortname != "lowgradefuel"
                // Ignore if the fuel amount is unexpected, since a mod likely adjusted it.
                || fuelItem.amount != fuelItem.info.stackable / 5)
                return;

            var hookResult = Interface.CallHook("OnVendorHeliFuelAdjust", heli);
            if (hookResult is bool && (bool)hookResult == false)
                return;

            fuelItem.amount = 100;
            fuelItem.MarkDirty();
        }
        catch (Exception ex)
        {
            // Log the error message
            Puts($"Error adjusting fuel for heli: {ex.Message}");
        }
    });
}

Didn't work for me.