I’m using the latest version of ClosedXML from NuGet: .102.3. I can open some spreadsheets with ClosedXML, but there are many which I cannot.

I receive the following exception from either a network drive or a local drive.:

System.ArgumentOutOfRangeException HResult=0x80131502 Message=Specified argument was out of the range of valid values. Parameter name: A: is not recognized as a column letter Source=ClosedXML StackTrace: at ClosedXML.Excel.XLHelper.GetColumnNumberFromLetter(String columnLetter) at ClosedXML.Excel.XLAddress.Create(XLWorksheet worksheet, String cellAddressString) at ClosedXML.Excel.XLWorkbook.LoadCells(SharedStringItem[] sharedStrings, Stylesheet s, NumberingFormats numberingFormats, Fills fills, Borders borders, Fonts fonts, Dictionary`2 sharedFormulasR1C1, XLWorksheet ws, Dictionary`2 styleList, Cell cell, Int32 rowIndex) at ClosedXML.Excel.XLWorkbook.LoadRows(Stylesheet s, NumberingFormats numberingFormats, Fills fills, Borders borders, Fonts fonts, XLWorksheet ws, SharedStringItem[] sharedStrings, Dictionary`2 sharedFormulasR1C1, Dictionary`2 styleList, Row row) at ClosedXML.Excel.XLWorkbook.LoadSpreadsheetDocument(SpreadsheetDocument dSpreadsheet) at ClosedXML.Excel.XLWorkbook.LoadSheets(String fileName) at ClosedXML.Excel.XLWorkbook..ctor(String file, LoadOptions loadOptions) at ClosedXML.Excel.XLWorkbook..ctor(String file) at ClosedXML.Test.ClosedXML.Open() in C:\Data\Visual Studio\ClosedXML\ClosedXML.Test\ClosedXML.cs:line 16

Has anyone seen this problem?