When I attempt a substructure search, after entering the structure, Chem3D comes up in the background, and then an error message 'no element tables are available'. It is then not possible to quit ChemDraw, as this message reappears at each attempt to quit. I have to force quit.
Check your system to make sure that you do not have more than one copy of Chem3D installed. In either case, make a back up of all of your personal files, and then delete all installed versions of our software. Do a Find File to make sure there are no Chem3D items left. Once all of the files have been removed, reinstall the software.