Error on calling 'OnStateChange' method: Object reference...

[xtremel]

I trying to modify the quantity for different instruments, but every time that I add this

            else if (Instrument.MasterInstrument.Name == "NQ" || Instrument.MasterInstrument.Name == "MNQ")
            {
                Quantity1            = 3;
                Quantity2            = 1;
                Quantity3            = 1;
                Quantity4            = 1;
            }
            else if (Instrument.MasterInstrument.Name == "ES" || Instrument.MasterInstrument.Name == "MES")
            {
                Quantity1            = 4;
                Quantity2            = 2;
                Quantity3            = 1;
                Quantity4            = 1;
            }​

I get this error

Error on calling 'OnStateChange' method: Object reference not set to an instance of an object.

        protected override void OnStateChange()
        {
            Print(State);        

            if (State == State.SetDefaults)
            {
            ....
            }
            else if (State == State.Configure)
            {
            ....
            }
            else if (State == State.DataLoaded)
            {                
                Quantity1            = 1;
                Quantity2            = 1;
                Quantity3            = 1;
                Quantity4            = 1;
            }
            else if (Instrument.MasterInstrument.Name == "NQ" || Instrument.MasterInstrument.Name == "MNQ")
            {
                Quantity1            = 3;
                Quantity2            = 1;
                Quantity3            = 1;
                Quantity4            = 1;
            }
            else if (Instrument.MasterInstrument.Name == "ES" || Instrument.MasterInstrument.Name == "MES")
            {
                Quantity1            = 4;
                Quantity2            = 2;
                Quantity3            = 1;
                Quantity4            = 1;
            }
        }​

[NinjaTrader_BrandonH]

Hello xtremel,

Thanks for your post.

How are the Quantity variables being declared in your script?

If you are trying to set the Quantity variables within State.DataLoaded based on a condition, you would need to add your Instrument conditions inside the 'else if (State==State.DataLoaded)' condition.

The error message "Object reference not set to the instance of an object" means that something in the script is returning null at the time you are accessing it. Debugging steps would need to be taken to determine what exactly is returning null in the indicator.

Below is a link to a forum post that demonstrates using debugging prints to understand the behavior of a script.
https://ninjatrader.com/support/foru...121#post791121

OnStateChange: https://ninjatrader.com/support/help...tatechange.htm

Let us know if we may assist further.

[xtremel]

Thank you Brandon!!!

Adding this else if (State==State.DataLoaded) fixed the issue.

            else if ((State==State.DataLoaded) && (Instrument.MasterInstrument.Name == "ES" || Instrument.MasterInstrument.Name == "MES"))