Here are a few things you can try: First, with Force-TLS '''installed,''' try removing the affected domains using the Force-TLS config screen. To do this, bring up the configuration screen (Firefox->tools->ForceTLS Settings), click on the affected site, then click "Remove Site". If that doesn't work, next try removing all sites. There's a button for that in the Force-TLS configuration screen. If both of those approaches don't work, you may have a corrupt permissions database. To rebuild your permissions database, follow these steps: # In Firefox open a new tab, and go to the web site "about:support". # In "Application Basics" there's a button to open your Profile Directory. # Click the button, and when it opens, open your profile directory and look for a file called "permissions.sqlite" -- delete that "permissions.sqlite" file or move it somewhere outside your profile directory. # Quit Firefox and re-launch it. Hopefully one of these three approaches will solve your problem!