I used Aspose.Cells 188.8.131.52 to generate an Excel file (no templates). On the first row that we treat as "data", there is an empty cell that is formatted as "Custom m/d/yyyy h:mm", according to Excel. (I used the Aspose style 22 -- datetime -- to do this.)
When I read this file into a MemoryStream and use that stream to open the document using an Excel object, I am finding that the empty datetime cell is now seen by Aspose as a Type "IsNull" with a value null. And so, when I write this document to disk again, the original styling is lost.
What is happening? I don't have a small test case to share, as this is part of a larger application.