What you see
One of: “That PDF could not be read.”, “This document could not be read. It may be password protected or damaged.” or “That PDF could not be opened. It may be encrypted or damaged.”
Why it happens
- It is not really a PDF. A file renamed to .pdf, or a web page saved with a .pdf name, looks like a PDF but is not one.
- The file is incomplete or damaged. A download or email attachment that was cut short leaves a file missing its end, and the end of a PDF is where its table of contents lives.
- It is locked with a password. A PDF that asks for a password before it opens is encrypted, and these tools cannot unlock it. A PDF that opens without a password but blocks printing or copying is encrypted too; some tools can still work on it, but check the result carefully.
What to do
- Open it in your PDF reader first. If the reader cannot open it either, the file is damaged: download it again or ask the sender for a new copy.
- Find out whether it is encrypted. The PDF Document Inspector reads the file without changing it and reports “Encrypted: Yes — a password is needed to open it” or “Yes — it opens without a password, but may restrict printing, copying or editing”.
- Make an unlocked copy — if the document is yours to change. Open it in your PDF reader with the password, then print it to a new PDF (choose Save as PDF, or Microsoft Print to PDF, as the printer). The copy has no password, as long as the document allows printing. Alternatively, remove the password in the program that set it.
- Try again with the new copy.