The information in this article applies to:
I am not able to select the Glass Doors option in my cabinets' specification dialogs. How do I specify glass doors when the option is grayed out?
The Glass Doors checkbox option will be grayed out if you are using a Panel for the cabinets door Style.
Alternately, you can select the Library button next to the Door Style to display the Select Library Object dialog and browse or search for a variety of different glass door options.