Hi, the issue hit me again and I could nail it down to localization package thunderbird-l10n-de 1:60.0-3~deb9u1
Lightning is up and running when using: LANG="en_US.UTF-8" /usr/bin/thunderbird Lightning vanished when using LANG="de_DE.UTF-8" /usr/bin/thunderbird After purging thunderbird-l10n-de lightning is also up and running using: LANG="de_DE.UTF-8" /usr/bin/thunderbird The steps I reported in my previous mail were done from console with en_US.UTF-8 locale. Therefore it worked. -- cheers, Steffen
