A: You can open the PDF document with UPDF, right-click on the document, click "Document Properties," go to the "Security" section, and check if the "Permissions Password" is set to "Allow." If it's set to "No," it indicates that the document is password-protected, and you'll need a special tool to unlock it. If you have further questions, feel free to contact support@superace.com, and we’ll be happy to assist you.