I have the same problem with the UK NHS website, which will not allow me to login and order more lateral flow test kits. [https://www.gov.uk/order-coronavirus-rapid-lateral-flow-tests https://www.gov.uk/order-coronavirus-rapid-lateral-flow-tests] The login page comes up blank with [https://access.login.nhs.uk/enter-email https://access.login.nhs.uk/enter-email] Deleting the '/enter-email' in the link above allows me in. I tested with Edge and that works with no problems. All was OK until the most recent Firefox update prior to version 96.0; I tried with all addons off, to no avail.

Unfortunately, removing “/?source=email” does not solve my problem with the Firefox browser in any way.

Make sure you are not blocking content. https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop also see https://blog.mozilla.org/security/2021/03/23/introducing-smartblock/ https://support.mozilla.org/en-US/kb/smartblock-enhanced-tracking-protection --------------- [https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode Diagnose Firefox issues using Troubleshoot(Safe) Mode] {web link} A small dialog should appear. Click '''Start In Troubleshoot(Safe) Mode''' (not Refresh). Is the problem still there? Many site issues can be caused by corrupt cookies or cache. '''Warning ! ! ''' This will log you out of sites you're logged in to. You may also lose any settings for that website. * [https://support.mozilla.org/en-US/kb/delete-cookies-remove-info-websites-stored Delete cookies to remove the information websites have stored on your computer] {web link} * [https://support.mozilla.org/en-US/kb/how-clear-firefox-cache How to clear the Firefox cache] {web link}