“External table is not in the expected format.” typically occurs when trying to use an Excel 2007 file with a connection string that uses: Microsoft.Jet.OLEDB.4.0 and Extended Properties=Excel 8.0
Using the following connection string seems to fix most problems.
public static string path = @"C:\src\RedirectApplication\RedirectApplication\301s.xlsx"; public static string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" +