Fixing broken Messages on OS X Mavericks

Solution 1:

Yes, copying the files from another computer should be fine, providing both computers have the same version of Messages.

There is a certain amount of leniency with this though, depending on where the files are that you deleted. For example, files in your home folder are expected to be backward-compatible since if you've upgraded your OS then it must know how to update the files.

Also, once you've copied the files, make sure you set the permissions correctly…

• If you've copied files to /Library, use Disk Utility to repair permissions.
• If you've copied files to ~/Library, use the ACL tool on the Recovery HD.