How to open SpreadsheetDocument without calcchain.xml

[tomjebo]

Discussed in #1279

^{Originally posted by Distancehe December 22, 2022}
The Excel file itself do not contain calcchain.xml, but calcchain.xml is referenced from workbook.xml.rels as below snapshot. When trying to load the excel with SpreadsheetDocument.Open(), it will throw exception since the calcchain.xml is missing. The question is, how to open the excel file with calcchain.xml missing? Is there some way to ignore this and continue open the file ? Thanks !