The ChemDraw for Excel Add-in is not loaded and when added manually the buttons do not work.
Recent updates from Microsoft seem to have affected several versions of MS Office, conflicting with the ChemDraw Add-in. In order to correct this problem you must perform a clean installation of both, MS Office and ChemDraw / ChemOfice.
First uninstall ChemDraw or ChemOffice. Then follow the instructions on this website to remove MS Office:
Finally reinstall ChemDraw and test it.