The following is copied word for word from apmouse‘s answer on stackexchange.com.

Under special circumstances, Mac OS X adds the extended attribute ‘com.apple.quarantine’ to a file which was e.g. downloaded from the internet. This can also happen to files within the BoxCryptor Folder. If an encrypted file has this extended attribute set, you receive the “is damaged” error message when trying to open the plaintext file in the BoxCryptor Volume.

x) Open Terminal (Applications -> Utilities)

y) Run the following command (substitute the path):

$ xattr -r -d com.apple.quarantine /path/to/encfs/mount/point

Source: http://apple.stackexchange.com/questions/129966/files-wrongly-considered-as-damaged-in-encfs-volume

Sometimes I will just apply this to a whole directory of my photos:
xattr -r -d com.apple.quarantine *

• Uncategorized