I'm getting error:

> 
> Excel cannot open the file 'FILE.xlsx' because the file format or
>  file extension is not valid. Verify that the file has not been
>  corrupted and that the file extension matches the format of the file.
> 
> 
> 

I suspect the reason is due to the fact that on File.xlsx I have a OleDBConnection using it and that later in the same code I call the Interop function Open of Excel on that file. Can someone confirm my theory?

```
public ExcelWorkbook(string file)
    {                       
        fileName = file;

        using (var workbookConnection = new OleDbConnection(String.Format(Resource.ExcelConnectionString, file)))
        {
            workbookConnection.Open();
            tabNames = GetDataTabsName(workbookConnection);
            foreach (string tabName in tabNames)
            {
                var newExcelTab = new ExcelTab(workbookConnection, file, tabName);
                excelTabs.Add(tabName, newExcelTab);
            }
        }
    }

```

Then my function GetDataTabsName(workbookConnection);

```
private List<string> GetDataTabsName(OleDbConnection workbookConnection)
    {
        var tabsName = new List<string>();
        var tabName = "";

       Excel.Application excelApp = new Excel.Application();
        excelApp.Visible = false;
        Excel.Workbook workbook = excelApp.Workbooks.Open(workbookConnection.DataSource, 0, false, 5, "", "", false, 
            Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "", true, false, 0, true, false, false);
....some more code

```

The Open fails here...and my best guess is that because an OleDBConnection is exist on that file??