Update on 2014-02-16: I’ve found a fix for the issue. Run this command in the terminal:
xattr -d com.apple.quarantine filename where
filename is the path to and name of the problem file.
I’ve bumped into an interesting issue on my OS X. The Preview.app couldn’t open PDF files:
X.pdf is damaged and can’t be opened. You should move it to the Trash.
It started a few weeks ago, and only PDFs newer than that date couldn’t be opened. All the older ones got opened just fine.
What’s strange, Safari couldn’t open the PDFs either, but they rendered perfectly fine by Quick Look. Even PDFs created by Preview itself and saved to disk, failed to open. It hit me that I’d upgraded the OS X to 10.9 at approximately the time it started. Console.app showed this line when Preview failed to open:
I couldn’t find a solution to this particular problem, and followed the best advice: disabling the Gatekeeper (it turned itself on when upgrading, by the way). Magic: when I set it to Anywhere, the PDFs are opened fine now.
BTW, I set the option back to Mac App Store and identified developers, and couldn’t reproduce the issue anymore.