Here is the link for all versions: https://addons.mozilla.org/en-US/firefox/addon/https-everywhere/versions/ This extension was bundled with the TOR browser. As you can see from the attached image, there is something wrong. I removed version 2019.6.27 and tried the slightly older 2019.6.4. That seemed to fix the problem. When I clicked on the toolbar button all appeared normal. When I closed and opened TOR browser the info box for HTTPS Everywhere was empty again. It's possible this extension will never work properly with TOR browser. If there is a solution, please provide the procedure.