Error while opening an excel workbook using C# code

(Sorry for answering this old question, but it's google result #1 for this problem and the correct answer is missing).

The error occurs because excel thinks the Workbook has been corrupted. When opening the Excel file, the last parameter tells excel how to handle this situation. Pass Microsoft.Office.Interop.Excel.XlCorruptLoad.xlExtractData to instruct it to retrieve the data (This will open a popup telling the user excel tried to extract the data if the file is corrupted).

However, I noticed this problem can also be caused if the workbook you are trying to open has a different locale than your excel (was saved on a machine using another language setting) OR your system not having the en-us locale set.

While this is extremely stupid, it's easy to overcome. For me the solution was to just set the current locale to en-us before opening the file:

static System.Globalization.CultureInfo oldCI;
oldCI = System.Threading.Thread.CurrentThread.CurrentCulture;
System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US");
xlWorkBook = xlApp.Workbooks.Open(filePath, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, Microsoft.Office.Interop.Excel.XlCorruptLoad.xlExtractData);
System.Threading.Thread.CurrentThread.CurrentCulture = oldCI;

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What if you try System.Reflection.Missing.Value instead of Type.Missing?

Regards,

M.

Which class are you using?

Microsoft.Office.Interop.Excel.ApplicationClass

if this then try changing it to

Microsoft.Office.Interop.Excel.Application

In case it helps someone else, I lost tons of time on this one. I was passing Microsoft.Office.Interop.Excel.XlCorruptLoad.xlRepairFile for the CorruptedLoad parameter for all files, thinking it meant "open the file, and if it's corrupt, attempt a repair". This worked for most files.

However, for some files, I was still getting the exception (Exception from HRESULT: 0x800A03EC). Yet if you open the file in Excel manually, it is not corrupt.

It turned out that for those files, you must not supply the CorruptedLoad parameter. Then it opens successfully. So in the end I adjusted my code to first try without any CorruptedLoad parameter, and only if that returns the exception, then try passing xlRepairFile for that parameter. I also adjusted my understanding of that parameter to mean "open and repair this file regardless of whether it's corrupt".