CambridgeSoft has released ChemBioDraw 12.0.3 for Mac. This version addresses bugs with version 12.0.2, including problems with the registration screen. This release can be downloaded at:
http://www.cambridgesoft.com/services/DesktopSupport/Downloads/
A CambridgeSoft login is required to download this update. Select "ChemBioDraw" as the Product. Follow the Mac installation instructions to install the update.