Can't print, copy or edit a PDF? What permission restrictions are
Some PDFs open freely but block printing, copying text or editing. That is a permission restriction, a different thing from a password to open the file.
Password to open vs permissions
A user (open) password stops anyone without it from reading the file. A permissions (owner) setting lets anyone open the file but asks software to block printing, copying or editing. Many files have only the second kind.
Why they exist
Authors use them to discourage copying or changes. They are a request that well-behaved software honours, not strong security, so removing them from a file you own, or have permission to change, is routine.
How to remove them from your own file
If the file is yours, open it and use the tool you made it with to re-save without security. If you no longer have that tool, UnsealPDF removes permission restrictions without needing a password: add the file, confirm you are allowed to change it, and check the verified result before you pay (From $1.99 per job, charged only after the result is verified).
When not to
If a document comes from someone else with rules about changing it (for example a licensed or confidential file), follow those rules. UnsealPDF asks you to confirm you have the right before it processes anything.
Questions
Why can I open my PDF but not print it?
It has a permission restriction (an owner setting) that blocks printing. It is separate from a password to open the file.
Do I need a password to remove permission restrictions?
Usually not: the file already opens without one. UnsealPDF removes the restrictions on files you own or may change.