OutLook COMException 0x800401E3 (MK_E_UNAVAILABLE)

I'm trying an ASP.NET App and I have a problem with OutLook.

Code behind :

public Outlook()
{
    // Check whether there is an Outlook process running.
    if (Process.GetProcessesByName("OUTLOOK").Count() > 0)
    {
        // If so, use the GetActiveObject method to obtain the process and cast it to an Application object.
        OutlookApplication = Marshal.GetActiveObject("Outlook.Application") as Application;
    }
    else
    {

        // If not, create a new instance of Outlook and log on to the default profile.
        OutlookApplication = new Application();
        NameSpace nameSpace = OutlookApplication.GetNamespace("MAPI");
        nameSpace.Logon("", "", missing, missing);
        nameSpace = null;
        }
    }
}

When I play the app then :

System.Runtime.InteropServices.COMException (0x800401E3): Opération non >disponible (Exception de HRESULT : 0x800401E3 (MK_E_UNAVAILABLE))

I already read this :

I would guess that you are running Visual Studio as Administrator (started via Run as Administrator) while Outlook was opened as user, who was logged in as under Windows logon. So the Visual Studio is running under different user than Outlook client.

But I dont know how to fix it.