Here is my code
It fails on the AddCopy method with an error “Value cannot be null. (Parameter ‘key’)”
Stack trace
at System.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
at System.Collections.Generic.Dictionary2.FindValue(TKey key) at System.Collections.Generic.Dictionary
2.TryGetValue(TKey key, TValue& value)
at GemBox.Spreadsheet.CellStyleCollection.(Style )
at GemBox.Spreadsheet.CellStyleCollection.(e , Boolean )
at .e(ExcelWorksheet , ExcelWorksheet )
at …ctor(ExcelWorksheet , ExcelWorksheet , )
at GemBox.Spreadsheet.ExcelRowCollection…ctor(ExcelWorksheet , ExcelRowCollection )
at GemBox.Spreadsheet.ExcelWorksheet…ctor(String , ExcelWorksheetCollection , ExcelWorksheet )
at GemBox.Spreadsheet.ExcelWorksheetCollection.(String , Int32 , ExcelWorksheet )
Version 49.0.1655