UNABLE TO ADD CUSTOM ACTION USING CODE IN GRAPH EXTENSION

The below custom code is not working in SOOrderEntry graph extension when I upgraded my customization to 24R1 version, though the same code is working fine in SOInvoiceEntry graph extension in save version

I am trying to add action menu item.

public override void Initialize()
{
    base.Initialize();
    this.Base.action.AddMenuAction(recalculateCPPriceAction);            
}

Below is the error and screenshot

Below is my SOOrderEntry graph extension structure

Can anyone help me out with this issue, I am confused about its working in anothe graph extension(SOInvoiceEntry) but not working in SOOrdrEntry graph extension in the same project.

Thanks and Regards

SD