Mozilla TLS Error Anonymous 4 years ago updated 4 years ago Answered Noob here, so I hope this is an easy fix. I recently added SSL/TLS certificate to my Wordpress Site using Really Simple SSL plug-in. The site is now loading with fine with HTTPS on Chrome, Edge, and Brave browsers. But on Firefox (mobile and desktop), I'm getting the following error: MOZILLA_PKIX_ERROR_REQUIRED_TLS_FEATURE_MISSING. The only information I can dredge up is that the OCSP Stapling (and no, I don't know what that is) is having issues and the problem is likely on the hosting side rather than the certificate. Any advice on what needs to be done so the site loads on Firefox as well?