Error on calling 'OnStateChange' method

[kdw2493]

Hi,

I built a simple strategy using the wizard but when I test the strategy, I get an error in the output saying

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

The only code in that block was generated by the wizard. This is where the profit target is being set. Any ideas on what is causing this?

For information, I am using Version 8.0.5.2 64-bit on Windows 10

else if (State == State.Configure)
			{
				SetProfitTarget(@"L1", CalculationMode.Price, DonchianChannel1.Mean[1]);
				
				SetProfitTarget(@"S1", CalculationMode.Price, DonchianChannel1.Mean[1]);
				SetStopLoss(@"L1", CalculationMode.Price, (DonchianChannel1.Lower[1] - (ATR(14)[0])) , false);
				SetStopLoss(@"S1", CalculationMode.Price, (DonchianChannel1.Upper[1] + (ATR(14)[0])) , false);
			}

When I debug it through Visual Studio, I get this message

An exception of type 'System.NullReferenceException' occurred in NinjaTrader.Core.dll but was not handled in user code

Additional information: Object reference not set to an instance of an object.

Can anyone help? I don't know where to start with this one

Thanks

[NinjaTrader_ChelseaB]

Hello kdw2493,

The error is occurring due to DonchianChannel1 (which I am assuming is assigned the indicator from a call to DonchianChannel() elsewhere in the script) in State.Configure before any bars have been processed in OnBarUpdate.

The Strategy Builder calls SetProfitTarget() and SetStopLoss() once before the script starts with hard set values. It does not call these dynamically with new values once the strategy has started.

(edit)
Instead, if you would like to use the current bar's DonchianChannel values for the exit and continue using the Strategy Builder, you would need to use exit orders in the Actions section of the Conditions and Actions.
(Like ExitLongLimit, ExitLongStopLimit, ExitLongStop)

Alternatively, you could unlock the code and move the call for SetStopLoss/SetProfitTarget to OnBarUpdate one line before the entry order is called. (It is important to call the Set method before calling the entry.)

[kdw2493]

Solved

Hi Chelsea,

Thanks for coming back to me. I managed to solve the problem about an hour ago by moving the instructions into the OnBarUpdate section

Thanks a lot
Kevin