Hi

I tried to open the site as https://www.msn.com (note the https) and received an error message relating to Microsoft has mis-configuring a security feature (OCSP stapling) on their servers which got now cached in your local firefox installation.

In order to resolve that, please enter about:config into the Firefox address bar (confirm the info message in case it shows up) and search for the preference named security.ssl.enable_ocsp_stapling. Double-click it and change its value to false - this will degrade a security feature in Firefox, so please revisit it in a couple of days again after Microsoft has fixed their stuff and turn it back on again then.

Hi Before I could even attempt your suggestion, I opened it and added the https:// and it opened fine with the lock icon and it is now saying connection secure. Could Microsoft have fixed it ?? Thanks for your help

Microsoft needs to reboot or update all servers that have cached this expired certificate that is used to sign the OCSP response, so if you no longer experiencing this issue then the server that you used is probably fixed.