I would like to avoid to create a new profile because I have a lot of accounts and especially identities I would need to add again (according to there is no way to export identities). Unlike the discontinued Mozilla Sunbird and Mozilla Calendar extension, Lightning integrates tightly with Thunderbird. 175482276/ suggests to downgrad Lightning but I think this is not possible anymore because Lightning is now a part of Thunderbird, isn't it? Lightning is an iCalendar compatible calendar.

apt purge thunderbird -> apt install thunderbrid -> no effect Help -> More Troubleshooting Information -> Clear startup cache. When I add one of the missing network calendars the wizard works and adds the calendar but is is not listed afterwards in the Lightning tab on the left. Only one 'survived' which isn't listing any entries and which I can not unsubscribe (Rightclick -> 'Unsubscribe Calendar.' is grayed out).

Somehow the Thunderbird calendar / Lightning is broken after upgrading from 10/Buster to 11/Bullseye.īefore upgrading I had 3 added network calendars.

Mozilla lightning