error in type casting a ROT element into its type

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COM

C#3.5

casting

I have a COM Class which is registered in to ROT, through an other application i am fetching the instance of my com class from ROT and casting it to its type giving following error.

Unable to cast COM object of type 'System.__ComObject' to interface type 'ROTViewer.IHandleVIParentInfo'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{C4B3F18E-FDF1-3F0C-A6DB-F03B302CAE9F}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).


Following is my COM class implementation

 public interface IHandleVIParentInfo
{
    Dictionary<int, string> ContainerParentredVi {get; set;}
    int GetListCount();
}

[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
[ComSourceInterfaces(typeof(IHandleVIParentInfo))]
[ProgIdAttribute(&quot;Qcs.VIParentedInfoHandler&quot;)]
[GuidAttribute(HandleVIParentedInfo.Guid)]
[DisplayName(&quot;Qcs VI Parented Info Handler&quot;)]
public class HandleVIParentedInfo : IDisposable, IHandleVIParentInfo
{
    public const string Guid = &quot;CB6BFC97-F8E3-4fce-B68B-4D01485811A1&quot;;
    public Dictionary&lt;int, string&gt; ContainerParentredVi
    {
        get
        {
            return _containerParentredVi;
        }
        set
        {
            _containerParentredVi = value;
        }
    }
    private Dictionary&lt;int, string&gt; _containerParentredVi = new Dictionary&lt;int, string&gt;();
    public HandleVIParentedInfo()
    {
        //private Dictionary&lt;int, string&gt; _containerParentredVi = new Dictionary&lt;int, string&gt;();
    }

    #region IDisposable Members

    void IDisposable.Dispose()
    {
        throw new NotImplementedException();
    }

    #endregion

    #region IHandleVIParentInfo Members

    int IHandleVIParentInfo.GetListCount()
    {
        return ContainerParentredVi.Count;
    }

    #endregion
}</pre>

Following is method where i am type casting an object to my com class type

        public static void GetIDEInstances()
        {
            instances = new List<object>();
            Hashtable runningStationInstances = new Hashtable();
            Hashtable runningObjects = GetROTContent();
           
            
            object expectedObj;
            //runningObjects["!{5EB461D8-71CD-4E78-A360-4CE788A93063}"].GetHashCode();
            IDictionaryEnumerator rotEnumerator = runningObjects.GetEnumerator();
            while (rotEnumerator.MoveNext())
            {
                string candidateName = (string)rotEnumerator.Key;
                if (string.Compare(candidateName,"!{CB6BFC97-F8E3-4fce-B68B-4D01485811A1}",true)==0)
                {
                    
                    viParenting = (IHandleVIParentInfo)rotEnumerator.Value;
                    
                   
                }
            }
}

getting error in the line "viParenting = (IHandleVIParentInfo)rotEnumerator.Value;"