Ancient Library of PDF 1.1 documents

I have a library of PDFs that were created in 1995, secured with PDF 1.1 encryption (/R 1) … I want to update them and re-secure them programmatically. I can’t seem to get them to open with the library. Does the library support encrypted PDFs that old or am I doing it wrong?

Hello;

PDFNet Should theoretically support 1.1 PDF files. If you aren’t getting them to work could you send us one of the PDF files and the Password to open it so we can check it out internally?

As I assume you may not want to just post this file and password on a public forum you can also contact us via the Web-Form here; PDFTron Systems Inc. | Form
This will create a ticket in our support ticket system, which will be private.

Best Regards;
-James