Help in this forum does not depend on any donations. Every member is treated the same way, of course it's easier to help the more informations we get. "New installation" does it mean that you uninstalled and reinstalled the program Thunderbird? Or was it an installation "from scratch"? First test: run TB in "troubleshoot mode" https://mzl.la/3AbU5jz

Thank you, Mapenzi! Meanwhile I reinstalled Thunderbird (after uninstallation) successfully, using an other source for the download that worked. And everything is fine, just as before. As for my remarks about the donation: trying to joke... not so good... nevertheless, I did it, after using mozilla for many years. Kind regards, Uli H. from Germany

Always download Thunderbird versions from official web sites such as https://www.thunderbird.net/de/download/ or http://ftp.mozilla.org/pub/thunderbird/releases/ and from Heise online... So your donation remark was second degree humour!