Unable to cast COM object of type 'Microsoft.Office.Interop.Excel.ApplicationClass' - Microsoft Q&A (2023)

Trevor Strike 1Reputation point

1. 

   Trevor Strike 1Reputation point

   2022-05-19T19:27:42.32+00:00

   Here is my code if needed part 1:
   using System;
   using System.IO;
   using System.Threading;
   using System.Windows.Forms;
   using Excel = Microsoft.Office.Interop.Excel;
   using static MoodysBasketPull.MBPMainMenu;
   using static MoodysBasketPull.APICalls;

   namespace MoodysBasketPull
   {
   class EssbaseLoadPrep
   {
   //Create variables used throughout the script and set those that need to be glaobally set
   private static readonly Excel.Application xlapp = new Excel.Application();
   private static readonly string txtPrepFileName = @\easnas.hban.us\FinanceFIT\Moodys\MoodysEssbasePrepFiles\EssbaseLoadPrep.txt;
   private static Excel.Workbook xlworkbook;
   private static Excel.Workbook xlworkbookN;
   private static Excel.Worksheet xlSheetN;
   private static Excel.Worksheet xlSheet;
   private static Excel.Range xlRange;
   private static DialogResult result;
   private static string Scenario;
   private static string Frequency;
   private static readonly string ESBLoadPath = @"\" + EssbaseServer + @"\D\inetpub\ftproot\Moodys\EssbaseProcessFiles\";
   private static string ESBLoadFileName;
   private static string ESBLoadPrepErrFileName = @\easnas.hban.us\FinanceFIT\Moodys\MoodysEssbasePrepFiles\ErrorLogs\;
   private static string msg;
   //Create stream writers for writing the data to
   private static StreamWriter EssLoad;
   private static StreamWriter EssLoadErr;

2. 

   Jack J Jun 19,821Reputation points • Microsoft Vendor

   2022-05-20T06:59:21.613+00:00

   (Video) Unable to cast COM object of type 'System ComObject'

   @Trevor Strike , Welcome to Microsoft Q&A, based on my test, there is no error for me when I tested the following code for 32 bit office.

   Excel.Application application = new Excel.Application(); 

   Do you have other code to generate the error?

   I noted that you used Microsoft Excel 16.0 Object Library, but I also find another method to call the Excel.Application by using the following method:

   Please install nuget-package Microsoft.Office.Interop.Excel.

3. 

   Trevor Strike 1Reputation point

   2022-05-20T12:51:19.387+00:00

   @Jack J Jun - Thank you for your response. I will try that and let you know if that works.

4. 

   Trevor Strike 1Reputation point

   2022-05-20T12:53:45.43+00:00

   Here is the rest of the code:
   //Opens File just exported from Moody's
   public static void OpenExcelFile(string FileExcel)
   {
   //Update ProcessMsgLabel
   msg = "Opening file exported from Moody's";
   UpdateMsg(msg);
   //open Moody's file that was just exported
   xlworkbook = xlapp.Workbooks.Open(FileExcel, ReadOnly: true, IgnoreReadOnlyRecommended: true);
   }
   }
   }

   The last line is where the error comes up.

5. 

   Viorel 83,736Reputation points

   2022-05-20T13:25:52.88+00:00

   Did you check if 'Dim a As Excel.Application : Set a = New Excel.Application' etc. works as VBA macro in Excel or Word?

6. 

   Trevor Strike 1Reputation point

   2022-05-20T17:41:40.69+00:00

   @Viorel - Thank you for your response. Can you help me understand how this would help if I am using C# in Visual studio?

   Thank you

7. 

   Trevor Strike 1Reputation point

   (Video) Unable to cast COM object of type System.__ComObject to IRibbonUI. IID...

   2022-05-20T21:55:07.393+00:00

   @Jack J Jun - I have installed nuget-package Microsoft.Office.Interop.Excel and removed the reference to the extension of Microsoft.Office.Interop.Excel, and got the same error. Do I need to delete the CPU assemblies again and recreate them, or is there something else I may be missing.

   Thank you

8. 

   Jack J Jun 19,821Reputation points • Microsoft Vendor

   2022-05-23T06:41:03.007+00:00

   @Trevor Strike , thanks for the feedback, I also tested the code you last posted, there is still no error for me. Then what is your current environment, I used the environment windows 10 1903.
   Also, I recommend that you could create a new app to install the nuget package to test the code instead of doing some changes in your oringinal app.

9. 

   Trevor Strike 1Reputation point

   2022-05-23T13:44:50.143+00:00

   @Jack J Jun - Thank you for continuing to look at this with me. We are using Windows 10 - 2009 as the company was told 1903 was at the end of support as of the end of May. Using Visual Studio Professional 2019 version 16.11.13. I am using .net version 4.7.2 as 4.8 crashed when I added a data source. The full application is built as a Windows form.

10. 

    Trevor Strike 1Reputation point

    2022-05-23T16:16:12.407+00:00

    @Jack J Jun - I tried creating a blank windows form, to run the process with a button to run the code for a specified file, but got the same error. The part that confuses me the most, is that the key being referred to is not in the registry, and it works great with my 64 bit. We are using Office 365 and are on version 2202 Build 16.014931.20392 for 64 bit and 32 bit office. Not sure if any of that matters, but hope this helps in trouble shooting. Is there a max file size I can open with the Interop process? Some of the files are 12+MB.
    Thank you for your help

11. 

    Jack J Jun 19,821Reputation points • Microsoft Vendor

    2022-05-24T02:18:48.59+00:00

    @Trevor Strike , based on the latest reponse, it seems that I found the difference between my environment and your environment. I used office 2016 instead of office365. Maybe that you could try to install office 2016 in the virtual machine to test the code if works for you.

12. 

    Ken Tucker 5,801Reputation points

    2022-05-24T08:34:51.233+00:00

    I always advise against automating office to open an excel file. I would recommend using the open source library NPOI or openxml sdk. Both allow you to open or create excel files without needing office installed

    (Video) Unable to cast object of type 'Microsoft.SharePoint.SPListItem' to type...

    http://www.independent-software.com/introduction-to-npoi.html

    https://learn.microsoft.com/en-us/office/open-xml/open-xml-sdk

13. 

    Trevor Strike 1Reputation point

    2022-05-24T13:53:48.687+00:00

    @Jack J Jun - Thank you for your response. Correct me if I am wrong, but is not office 365 when installed on a device the same as office 2016? All my office products are a hard install on the laptop or VDI. The only difference is that whether I am using the 64 bit version or the 32 bit version. I developed the windows form application on my laptop which is a 64 bit install of office. There the process works great. The issue is when I try to run the application on the 32 bit office install using the X86 or AnyCPU version, it does not work. Are you using 32 bit office or 64 bit office? I will try to create the process on my 32 bit office install to see if that allows for the process to work there.

    If you have any other ideas, please let me know.

    Thank you for your help.

14. 

    Trevor Strike 1Reputation point

    2022-05-24T13:53:58.1+00:00

    As a side note: Basically what I am trying to do is take a file that I get which has the data headers in column A and make them the row headers instead and then save the file as a text file so that I can read the data in and create a text file that has one row for each of the data points that are in the file. There are 900+ records that I am processing with data points for every month or quarter depending on the file from year 1960 to 2052 plus two date records. If there is a better way to do this than to open the file in excel do a copy transpose paste and a few formatting changes so that I get all the digits for the numeric values(formatting as "0.#######################;(0.#####################)"), and the dates are in numeric values when one is text and the other has only the last two digits (For these I have been using the text to columns option to get them the way I want them).

15. 

    Trevor Strike 1Reputation point

    2022-05-24T13:59:31.987+00:00

    @Ken Tucker - Thank you for your advice. I will look into these.

    Basically what I am trying to do is take an excel file that I get which has the data headers in column A and make them the row headers instead and then save the file as a text file so that I can read the data in and create a text file that has one row for each of the data points that are in the file. There are 900+ records that I am processing with data points for every month or quarter depending on the file from year 1960 to 2052 plus two date records. If there is a better way to do this than to open the file in excel do a copy transpose paste and a few formatting changes so that I get all the digits for the numeric values(formatting as "0.#######################;(0.#####################)"), and the dates are in numeric values when one is text and the other has only the last two digits (For these I have been using the text to columns option to get them the way I want them).

    This being said, I am not just opening the file but I am manipulating the so that the resulting text file is as I need it for processing.

    Any additional advice is greatly appreciated.

    Thank you

16. 

    Trevor Strike 1Reputation point

    2022-05-24T18:35:44.817+00:00

    Creating the application on my 32 bit office VDI did not change the situation. I still get the error whether I use the AnyCPU configuration or the x86 configuration.

    Thank you

17. 

    Jack J Jun 19,821Reputation points • Microsoft Vendor

    2022-05-25T08:27:16.503+00:00

    (Video) Sharepoint: Cannot open microsoft.office.interop.word document (2 Solutions!!)

    @Trevor Strike ,okay, I have provided many methods to try to solve your problem, but it all failed. Therefore,I will suggest that you could try other sdk to replace the interp api.

18. 

    Trevor Strike 1Reputation point

    2022-05-25T14:50:37.557+00:00

    @Jack J Jun - Thank you for your help. I have an additional question for you. Can you tell me the version of Visual studio you are using? I have a co-worker that used my code in his visual studio and the Microsoft.Office.Interop.Excel work for him, but he is using version 16.11.9 where I am using 16.11.11 and 16.11.15.

    Thank you

19. 

    Jack J Jun 19,821Reputation points • Microsoft Vendor

    2022-05-26T08:18:59.767+00:00

    @Trevor Strike , please refer to the following picture:
    

    I also used 16.11.15.