Upgrade Payment Plugin from 3.8 to 3.9

Hi, I have problem trying to upgrade a payment plugin from 3.8 to 3.9.

Class:

public class KlarnaCheckoutProcessor : BasePlugin, IPaymentMethod

I Added line in field region:

private readonly ILocalizationService _localizationService;

Added lines in Ctor:

ILocalizationService localizationService,

and

this._localizationService = localizationService;

I Added Property:

        public string PaymentMethodDescription
        {
            get { return _localizationService.GetResource("Motillo.Plugin.KlarnaCheckout.PaymentMethodDescription"); }
        }

        


And I added the Resources in Install and Uninstall methods.

Still I get this Server error:

[Exception: Plugin 'Klarna Checkout'. Method get_PaymentMethodDescription in Motillo.Nop.Plugin.KlarnaCheckout.KlarnaCheckoutProcessor from the Motillo.Nop.Plugin.KlarnaCheckout, Version = 1.2.0.0, Culture = neutral, PublicKeyToken = null Does not have an implementation
]
    Nop.Core.Plugins.PluginManager.Initialize () +2899

If I remove or comment out Property PaymentMethodDescription in my Processor class I wont get any compile error in VS2013, but I should?

What I'm I missing?

Find the issue, it was the path to nop.service ref. that was set to the old 3.8 solution