Figured it out. Amazing how much coffee and less stress help! For anyone else who has this issue, go to the hamburger (≡) menu on the upper right of the mail page, click on Tools, then Developer Tools. You may get a message that says: An incoming request to permit remote debugging connection was detected. A remote client can take complete control over your browser! Client Endpoint: 127.0.0.1:xxxxx Server Endpoint: 127.0.0.1:xxxxx Allow connection? This is from Thunderbird. If you don't allow the connection, your primary password cannot be reset. If you're not certain, don't allow it. If it's legit, you'll get an error message stating that the connection failed, and when you click "okay", you'll go back to your main mail page. You'll have to start over again. So, allow the connection once you're certain it's legit, then click on Debug (right-hand side, after Errors - Warnings - Logs - Info), then copy and paste this: openDialog("chrome://pippki/content/resetpassword.xhtml") and hit Enter on your keyboard. You'll have to click twice on Reset Primary Password. Once you do, you can either go back and make a new one, or leave it blank.