It does not upload new versions from 68.6.0 and asks you to download it. Then after deleting App from Applications and dragging new version into Apps the loader can be ejected, but comes out again as soon as you try and open the new App. It then offers you the chance to keep your existing profile, but the dock icon and the App in the Apps folder is not open properly. It is compromised by poor code as, otherwise it would load automatically on the upgrade, which it does not do. All the advice on Mozilla Support does not work with this problem. It seems that Thunderbird have given up any sense of integrity in this App. I have always been able ti update until 68.6.0. The code is wrong in the updates now and everone says that here is not a problem, but I have an iMac just over a year old and the latest OSX which is always up to date and my computer works flawlessly it's just that I have to say using 68.6.0 whether I like it or not.