No command will work from the Ribbon. I've changed workspaces and tried a backup CUI file. Is my system corrupt or is there some setting that displays the ribbon, but disables the commands within it?
I don't know of any command that will disable the Ribbon. I would first try repairing the install.
C3D 2012, RD 2012
Win 7 64, Core i7,
6 GB RAM, Quadro FX 1700