The File Is Damaged and Could Not Be Repaired

The damage almost always happens while the file is moved or saved:

• A download, sync or copy that stopped early. The end of a PDF holds the index readers need first, so a short file fails at once.
• An email attachment that didn't decode, or a file saved from a web page that was really an error page.
• Extra data before the PDF, such as a mail or web server header saved into the file.
• A program that wrote the PDF badly: wrong stream lengths or a cross-reference table that points to the wrong places.

If every PDF shows the error, the files are probably fine and Acrobat is the problem. See the next chapter.

Adobe's own help says that a PDF that is corrupt or damaged can't be repaired in Acrobat; it suggests recreating it from the original source. Before that, rule out Acrobat itself:

1. Update Acrobat or Acrobat Reader: choose Help, then Check for Updates.
2. On Windows, repair the installation: choose Help, then Repair Installation.
3. Download the file again, or ask the sender to send it again, and save it straight to your computer.

Menu names can differ between versions.

If it doesn't work

• Other PDFs open but this one doesn't: the file is damaged. Use the repair tool above, or open the file in another reader such as your browser.
• No PDF opens: reinstall Acrobat or Acrobat Reader.

When the index is damaged, Acrobat tries to rebuild it and sometimes gives up. The tool doesn't rely on the index at all: it scans the whole file for every object, keeps the newest copy of each, and writes a new cross-reference table and trailer that point to them. It also corrects stream lengths, page counts and the page tree, and removes junk saved before the PDF.

It doesn't change pages, text or images, and it doesn't remove passwords. See pdf repair for the full list of what it fixes and its limits.