Cannot use ConnectorPin 5 and 6

[tfsonic]

Hello together,

I'm using a Raspbery Pi 3 Model B and I have the following issue and I'm hoping that you can help me.
I would like to use Connector Pin 5 and 6 for a shutdown process.
So I have created the following instance:

InputPinConfiguration onOffBtn = ConnectorPin.P5Pin06.Input().PullDown();

onOffBtn.OnStatusChanged(state =>
{
     if (state)
        controller.Shutdown();
});

But I get always the following exception:
Unhandled Exception: System.InvalidOperationException: Connector pin P5-6 is not mapped to processor with pin layout revision Plus at Raspberry.IO.GeneralPurpose.PinMapping.ToProcessor (Raspbery.IO.GeneralPurpose.ConnectorPin pin) [0x00050] at Raspberry.IO.GeneralPurpose.PinConfigurationExtensionMethods.Input (Raspberry.IO.GeneralPurpose.ConnectorPin pin [0x00000]

I have tried a lot of steps, for example I have converted the ConnectorPin combination to a ProcessorPin, but that was not a solution for my problem.

What I'm doing wrong? Thank you so much for your help.

Greets
Timo