I am using Ubuntu 18.04 with latest Thunderbird (52.8.0). Normaly (in older verions of Thunderbird, like the one in Ubuntu 17.10), it was possible to just install a language like described here: https://support.mozilla.org/en-US/kb/how-do-i-use-firefox-spell-checker in order to use the spell checker in a different language. I clicked on "Sprachen -> Wörterbuch hinzufügen" and downloaded the german language packet. Now in "Add-ons-Verwaltung", there is "Deutsch (DE) Lanuage Pack", and it is activated. Unfortunately, if I right-click on any text, I still can not change to german. This did not change when restarting thunderbird. For "Wörterbuch" (Dictionary), the link for download is not present (while it is present for other languages, e.g. Afrikaans), but the link for "Sprachpacket herunterladen" keeps beeing there, even if I installed the language packet. There are other users complaining in the comments section of the language pack: https://addons.mozilla.org/de/thunderbird/addon/deutsch-de-language-pack-thund/ (e.g. "Sprachpakete lassen sich nicht installieren. Anwendung ist völlig unbrauchbar!" means "Language packets can not be installed. Application is not usable at all." which may be an exaggeration.). Is this still the right way to install a dictionary, or is the link to the dictionary maybe wrong? Can I install it somehow manually or by apt?