Site loaded through Proxy
When Convert Experiences loads a certain site into the Visual Editor, if the tracking code is not installed on the loaded site's page, a proxy would be used for technical reasons. In that scenario, instead of loading the site under your own URL (let's say http://www.example.com/page.html) we'll load it under a Convert Experiences URL (something like http://editor.convertexperiments.com/load/http://www.example.com/pa...). Doing that, some of the scripts on site may not load correctly due to the different URL used.
Note: the fact that certain things on page do not work while loaded in the Visual Editor does not mean they will not work on the real site. For that you must use the live preview function in order to make sure your variations render perfectly without issues.
In order to be able to browse without any problems your site while loaded in the Visual Editor and so that all the functionality is still there, you need in install the Tracking Code on any page you'd like to browse.