“Preview” is damaged and can’t be opened.

“Preview” is damaged and can’t be opened. You should move it to the Trash.

"Preview" is damaged.

This was the rather surprising error message that I’ve been getting when I try to open a PDF from the Finder since I upgraded to OS X Yosemite. It’s bad enough when you get an error message, but one suggesting that you delete a frequently used app is inconvenient to say the least!

Since I found it, I’ve been using a workaround: start Preview.app and open the file manually.

But there’s a better answer. Apparently it just has a duff “quarantine” attribute set. To get rid of it and get things back to normal simply do the following in a Terminal window:

/Users/stephend $ cd /Applications 
/Applications $ xattr -l Preview.app
com.apple.quarantine: 0006;53563f06;Acorn;
/Applications $

If you see the same thing, proceed to the next step:

/Applications $ sudo xattr -d com.apple.quarantine Preview.app

And that’s all. Now opening a PDF from the Finder should work. It’s bizarre.

I raised Radar 19384558 with Apple. Please dupe if you see the same thing. Thanks to Gus Mueller (developer of Acorn) for the support.

Update: It seems that a couple of other apps also have the same, incorrect attributes:

/Applications $ xattr -l *.app Utilities/*.app | grep Acorn       
Mail.app: com.apple.quarantine: 0006;53563f06;Acorn;
iPhoto.app: com.apple.quarantine: 0006;53563f06;Acorn;

I have also removed those tags, though I’ve not seen any problems with them so far.