ChemDraw has no plugin support for 64-bit web browsers. ChemDraw, if Active X plugin installed, can work fine in 32-bit Internet Explorer (11) or Firefox (older versions than Firefox 52) browsers. Note that ChemDraw has to be installed locally on your computer.
From Compound Registration version 20.8.0-2005111440 not just ChemDraw 15 and 16, but also ChemDraw 17 and 18 can be used successfully as structure editor within the Compound Registration web application.
According to PerkinElmer support from ChemDraw version 17 ChemDraw ActiveX Control is works with the following browsers:
Microsoft Internet Explorer 11.x (32bit and 64-bit)