Users of Artstor’s Offline Image Viewer (OIV) should be aware that it does not yet work with the newest Apple operating system, Mac OSX Mavericks (version 10.9). Artstor is aware of this incompatibility and is working to fix it, but it may be a few more months until a compatible version is available.
This is a problem that has happened before, and I can pretty much promise you that it will happen again the next time Apple moves to a new version of OSX. For the time being, I encourage OIV users to hold off on getting the free upgrade to Mavericks if at all possible. And please feel free to contact me if you need any help!