Updated to 140.10.0ESR now only get Secure Connection Failed

Just updated Firefox desktop (Win 10 with ESU) to 140.10.0ESR and now every site I try to access gives <blockquote>Secure Connection Failed An error occurred during a connection to www.google.com. PR_CONNECT_RESET_ERROR Error code: PR_CONNECT_RESET_ERROR The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem.</blockquote> Sites were all working fine literally right before. No other changes at all. Have restarted a few times. Have disabled antivirus and adblocker extensions. Same problem including at google.com and even firefox. Note on the About Mozilla Firefox window says " Failed to check for updates". Also cannot even use the links there to go to What's new or Firefox help etc. (Gives Secure Connection Failed error). No proxy server. Have tried turning anti virus completely off. Just a combined modem/router -- basically vanilla. Firefox is my primary browser so this is extremely disruptive. I am using Edge to access sites and post this.. though curiously enough I noticed it gave some error when checking for updates. Do not want to do anything there or will lose complete access. Any suggestions .. or how to go back to a previous version, if necessary. Need a workable connection to file taxes next week so this is important. Thank you. Moderator note: This question has been edited to correct the formatting.