Apple just released OS X 10.8, a.k.a. Mountain Lion, but if you’re running AutoCAD for Mac or AutoCAD LT for Mac you might want to hold off on that upgrade for a bit.
Currently the 2012 and 2013 versions of AutoCAD and AutoCAD LT for Mac are NOT supported on OS X 10.8. Installing it can cause issues with the installer, cursor, printing to PDF, and more.
Our team is working non-stop on an update that will provide support for Mountain Lion, but in the meantime we highly recommend that you stay with your current OS version.
The link below is to the official support document, and includes information on upcoming betas for Mountain Lion updates.