re :There is no release note for 78.3.0, Yes there is, release notes are always posted up at the same time as the actual new release version. https://www.thunderbird.net/en-US/thunderbird/78.3.0/releasenotes/

I presume you uninstalled the previous version of Antidote and then downloaded and reinstalled the latest version as per Antidote instructions. Then restarted Thunderbird. Please note: it is the responsibility of 'Antidote' to provide software that functions with the version of Thunderbird it claims to work with and if you are experiencing issues, that feedback should be passed on to Antidote explaining what works and what does not work. https://www.antidote.info/en/assistance/faq/questions/thunderbird-78

Hi, I have the same problem with antidote9. Antidote told me that correcting antidote 9 to make it work with thunderbird will actually make it unstable. Is there a solution such as I can keep using both? cheers

I believe there was a caching issue with the release notes - happens sometimes.

Please note, we stopped shipping 78.3.0. 78.3.1 will be out shortly

For now there isn't any solution from Antidote. At the moment, they are working on the problem/solution. From what they told me, when they have the update/solution, it will only adress antidote 10 version, because of the latest version/architecture of Thunderbird.

Hello there We have read your message We try to help you.

If you are using a previous edition, you will need to upgrade towards Antidote 10 to reestablish the integration in Thunderbird 78.

Greetings Firefox volunteer.

exactly it's for antidote 10, even then Antidote are working pretty hard to make it work on thunderbird 78