When attempting to access the Secure Access Cloud (SAC) portal in Firefox ESR (Extended Support Release), the page will appear to be "stuck" in a "Loading..." loop.
Secure Access Cloud
Firefox ESR is a relatively old and separate branch of FireFox releases that is being maintained by Mozilla for compatibility purposes. Modern Web UI platforms, such as Angular, support the latest branch of Firefox, but not the ESR branch.
Delete Firefox ESR and install the latest stable and secure version of Firefox from Mozilla.org. Please note, if you have an ESR version, there is not an automatic update path.