I tried the PDFAESEncOld from PDFEncAct and that works, makes an encrypted file that is opened with the reader. I do not see how PDFAESStream class works, especially the ImportFromFile and ExportToFile, these methods seem unfinished.
Can you, please, post the code that takes a PDF file, saves an encrypted version to disk and then opens the encrypted file and renders it? All this using code in version 2.9.10
1. open file1.pdf
2. save encrypted file1.pdf to file1encrypted.pdf
3. open file1encrypted.pdf and render it on screen.