02.08.2018 1422
On some Nginx installations the config file does not allow loading the chat widget on the website. Should that be the case even if you have whitelisted the domain you will need to edit the nginx config file.
add_header X-Frame-Options "SAMEORIGIN";
#add_header X-Frame-Options "SAMEORIGIN";
Save and reload the site, it should now load the chat widget as expected.