I have a similar problem as reported here: Digital signature doesn’t work after saving document
I’m using version 16.7.0.0.
In my attached sample I have demonstrated that I start with a very simple document, containing a small “AutoOpen” macro, that is showing a message box when the document is opened.
This macro module is digitally signed with a proper code signing certificate from DigiCert, used throughout my entire organization for various code signing purposes.
After a plain load/save operation in Aspose, without doing ANY operations, this digital signature is invalidated.
My expectation was this (at the bottom of the page): https://docs.aspose.com/words/net/working-with-digital-signatures/
Requirements for running this sample is to disallow all macros except digitally signed.