I am reading a creating an OpenXml SpreadsheetDocument from an external Excel file stream, and I add some formula and values.

However, when I try to save it to a stream, it loses most of its data and not capable of being opened.

Here is the code I used:

var stream= new MemoryStream();
.
.
.
spreadsheetDocument.WorkbookPart.Workbook.Save(stream);
stream = new MemoryStream(stream.ToArray());
stream.Position = 0;

return stream;