Artstor has released a new version of its Offline Image Viewer (OIV). For Mac users, OIV 4.0 is compatible with OSX Mavericks (version 10.9), but it is not yet compatible with Apple’s newest operating system, OSX Yosemite (version 10.10). So if you use OIV, I would recommend waiting to upgrade your system to Yosemite until Artstor has addressed this known issue.
You can find more information about new features in OIV 4.0, along with detailed instructions for installing it, in the Artstor Blog.