What does Unlock PDF not protect?

It removes permission flags only. It cannot decrypt user-password-protected PDFs. It is not a cracking tool.

What this does not protect

• Cannot decrypt PDFs that require a user password to open. The tool has no password input — it simply re-parses and re-saves.
• AES-256 encrypted PDFs with user passwords will fail completely. There is no brute-force or cracking capability.
• Some PDFs with unusual encryption handlers (non-standard, DRM) will fail to load.
• It cannot fix compromised devices, accounts, or unsafe sharing channels.