Hi guys, I have the same problem I read on a closed thread with no solution.
I checked all plugins and realize that SiteOrigin Page Builder (2.6.3) is causing the customizer of the Corp theme not load, and cant build pages with the plugin.
I tried local on MAMP and works well, but on a hosted install the combination of theme + plugin does not work.
It is a fresh WordPress installation. Theme and plugin are your latest releases.