3 ms·

Only if you're using a ridiculously outdated copy: changed Add-on support: Add-ons are only supported if add-on authors have adapted them changed Dictionary

• monocasa 6y ago
  Literally here's a doc explaining how XUL has changed as of Thunderbird 68, the most recent version, released about a month and a half ago. Yes, some elements have been removed, but others have been modified and still exist. https://developer.thunderbird.net/add-ons/updating/tb68/changes https://developer.thunderbird.net/add-ons/updating/tb68/chan... And that's in the add-on documentation, not even just internal development docs. Also, describing information changed in the most recent stable release, a month and a half ago, hardly qualifies any older as "ridiculously outdated ".