Hello there we have read the message We try to help you. https://archive.mozilla.org/pub/thunderbird/releases/ good day, you would like to roll back your Thunderbird version to a previous version? It is possible that you can roll back to a previous version of Thunderbird. It might give some issue . Most of the downgrade s are oké. what is the problem that you cannot continue with your Software Super Nova version? What version do you currently have on your PC, if I may ask? What was your last release of Thunderbird that worked? select your version. Then your operating system. Then the language you want. IE: en-US for US English. The click the .exe file. Greetings Firefox volunteer