unable to cast COM object of type 'microsoft.Office.Interop.Excel.ApplicationClass' to 'microsoft.Office.Interop.Excel.Application'"

Question

This is my first attempt to capture some data from excel from within one C# console application.

I get the error "unable to cast COM object of type 'microsoft.Office.Interop.Excel.ApplicationClass' to 'microsoft.Office.Interop.Excel.Application'".

This code used the 'Microsoft Excel 12.0 Object Library' , and I gave reference to Microsoft.Office.Interop.Excel.

Still, I could not get over this error - which I believe has its own quick solution.

I digged a little bit this site and came across with this solution: Interop type cannot be embedded

However, I could not understand so could not implement what was suggested as a solution.

My .Net version is 4.5.

Any help is very much appreciated.

Thanks in advance.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;

using Excel = Microsoft.Office.Interop.Excel;

namespace deneme
{
class Program
{
    static void Main(string[] args)
    {

        Excel.Application xlApp = new Excel.Application();
        xlApp.Visible = true; // <-- excel application
        xlApp.DisplayAlerts = false;

        // Open the workbook.
        Excel.Workbook wBook = xlApp.Workbooks.Open("C:\\FNN\\XLA\\fnnComTemplate.xlsx",
            Type.Missing, Type.Missing, Type.Missing, Type.Missing,
            Type.Missing, Type.Missing, Type.Missing, Type.Missing,
            Type.Missing, Type.Missing, Type.Missing, Type.Missing,
            Type.Missing, Type.Missing);

        // get the sheet
        Excel.Worksheet wSheet = wBook.Sheets[0];
        // foreach (Excel.Worksheet sheet in wBook.Sheets) { if (sheet.Name == "templateSheet") { wSheet = sheet; } }

        Excel.Range rng = wSheet.get_Range("A1");

        aux = wSheet.Range["F6"].Value;

        Console.WriteLine("interop result:" + aux);
        Console.ReadLine();

    }

}
}

Answer 1

If this is not a code related error than please remove below given key from registry.

Steps:

Start--> Run --> regedit --> HKEY_CLASSES_ROOT-->TypeLib-->{00020813-0000-0000-C000-000000000046} --> 1.8/1.7 (Delete this)

Solution: This issue can be resolved by deleting an invalid registry key left over from the higher version of Office. Follow the above steps.

Cause: This issue is caused by a left over registry key if you have downgraded your version of Microsoft Office from either Office 2010 to Office 2007, or Office 2013 to Office 2010 or 2007.

Let me know if this solution is not helped to you