Hi Aspose team,
We are using v20.3 lib. I signed an encrypted PDF, but there are no any signature information in the generated PDF, and then I attempted to view the generated PDF using Adobe Acrobat Std 2017. Acrobat states “At least one signature is invalid”.
BTW, I didn’t see any exceptions occured in the code while signing, it means that signing the PDF should be successful.
I prepared the code sample, the test pdf and the certificate. Please have a look . Thanks.