XmlHelper WriteAttribute DateTime? not implemented exception.

[dotnetninja74]

Is there a reason for the following to throw a not implemented exception?

public static void WriteAttribute(StreamWriter sw, string attributeName, DateTime? value)

[tonyqus]

I don't know the exact behavior of datetime serialization in openxml and I cannot find good examples of possible serialization case. Moreover, this method is only used in PivotTable definition. I don't see large demand for pivot support in NPOI.

[Myricaulus]

Well i just encountered the same error when trying to write the book. I actually didnt want to edit the sheet containing the pivot table, but another one. Is there a way to only open a sheet for editing? Or to find the culprit in the workbook and edit it somehow?