Call COM object from COBOL

Question

I am calling COM object (written in C#) from COBOL. But when I try to call it, I receive this error:

Exception 65540 not trapped by the class oleexceptionmanage
Description: "OLE Name not found"                          
(80020006): Unknown name.                                  
                                                           
Hit T to terminate program. Hit any other key to continue. 

This error happens when processing invoke of method GetDate. I have generated unique GUIDs, also I have COM object signed with generated snk file. I already done this type of call, and it's working. But with this module, I am missing something.

COBOL code:

class-control.                                               
  CharacterArray     is class "chararry"                     
  OLESafeArray       is class "olesafea"                     
  FileCrDat is class "$OLE$LLPFileCreateDate.FileCreateDate".
....
05 FileCrDatObj               object reference.
....
invoke FileCrDat "new" returning FileCrDatObj    
invoke FileCrDatObj "GetDate" using w-file-test  
 returning w-file-date                           
end-invoke

                                

C# code

using System;
using System.IO;
using System.Runtime.InteropServices;

namespace LLPFileCreateDate
{
    [Guid("057DAAB4-8D90-4C5F-922C-F0BEDC7C691C"),
    InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
    public interface IFileCreateDate
    {
        [DispId(1)]
        string GetDate(string file);
    }

    [Guid("39DDA4DD-9789-439F-BDD1-620AE0B3B1C5"),
    ClassInterface(ClassInterfaceType.None)]
    public class FileCreateDate : IFileCreateDate
    {
        public FileCreateDate() { }

        public string GetDate(string file)
        {
            DateTime dateCreate = File.GetCreationTime(file);
            string fileDate = dateCreate.ToString();
            return fileDate;
        }
    }
}

Answer 1

I found solution. Method name can't start with set or get word. Because when it is, it's treated differently as getter or setter.