If you see an endless spinning/loading indicator or a blank page, then this might be a simple URL configuration issue.

1. Make sure that the URL in your browser is the same as the URL set from Admin > Branding > Helpdesk URL. In particular, be sure that the protocols match. For example, if the URL of your helpdesk is using https:// (secure), make sure that your browser is also using https://.

2. In rare cases, the Help Center CSS file may become corrupt. In this case, use the Color Chooser to change any color (even slightly) and then apply it, then refresh your browser. This will make the system re-write the CSS files.