Hi &nbsp; !<BR> The problem lies with Microsoft, whose servers &nbsp; (in layman's terms) &nbsp; send an expired assurance that their SSL certificate is still valid. Unfortunately it turns out that Firefox is the only browser checking for this on each secure https site it is loading. (whereas other browsers glance over that and only check for : https://en.wikipedia.org/wiki/Extended_Validation_Certificate). If needed and if you want to, you can disable OCSP &nbsp; (for now) : Type in the address bar &nbsp; '''about:config''' &nbsp; (press Enter) (promise to be careful, if asked) Type and look for the preference : '''security.ssl.enable_ocsp_stapling''' and set it's value to &nbsp; '''false''' It is best to reset this pref via the right-click context menu to &nbsp; '''true'''&nbsp; once you are done with this website. -------------------------------------------------------------------------------------------------------- Also see : https://portal.office.com/servicestatus And : https://www.theregister.co.uk/2017/05/29/certificate_snafu_sees_azure_portal_reject_firefox/