Created Unassigned: HSSFWorkbook.Write occurred NPOI.HPSF.ReadingNotSupportedException [13247]

A first chance exception of type 'NPOI.HPSF.ReadingNotSupportedException' occurred in NPOI.dll
A first chance exception of type 'NPOI.HPSF.ReadingNotSupportedException' occurred in NPOI.dll

Twice