Visual Studio 2012 Item Template Wizard IWizard missing assembly problems

I' ve implemented a item template for a custom .H (C++ file) 

Then I proceeded to create the associated item template wizard for some customizations.

As required this class project uses the IWizard interface:

using System;
using System.Collections.Generic;
using Microsoft.VisualStudio.TemplateWizard;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using EnvDTE;

namespace DeviantHeaderWizard
{
    public class IWizardImplementation : IWizard

-Reference to the TemplateWizard assembly has been added, 

-the plugin has been registered using gacutil -i

-it has been referenced inside the vstempate using the gacutil -l output

When initiating a new file creation using my item template, i got the following message:

---------------------------
Microsoft Visual Studio
---------------------------
The vstemplate file references the wizard class 'CustomWizard.IWizardImplementation', which does not exist in the assembly 'DeviantHeaderWizard, Version=1.0.0.0, Culture=neutral, PublicKeyToken=c77c5cd352a10637'.
---------------------------
OK   
---------------------------

After searching a long (somewhat long(very long time)), i cannot figure out what s wrong !!

I Checked the platform target (which used to be anycpu), that i turned to reflect my env settings (x64, but same result.

Any help is welcome