Hello

Yes , it can be there that after certain Thunderbird software version update s that had settings that belong in the kalander section are gone. The reason that these old kalander settings did not make it to update them along from the old version to the another newer version the latest version of Thunderbird, is that it might be there that add ons that where there probably has being outdated there or files where corrupted at times in the previous version s of Thunderbird or some old conflicting extension s where there present to somehow to interrupt that update process. It ain’t a misspell or a sort of error . It just where there without knowing the fact of being there. You toke the update and there you are. A new version of Thunderbird without the old setting or reminders from that kalender. There might be a complete list from these unknown missettings when the update arrives. It ain’t harmful for the update but in some cases they are missing , yes correct.

Hello there

Look in the thunderbird settings and go to the kalander settings and click kalender, look for enabling missed reminders and enable them there if possible then look for that option to have in text show missed reminders, it also could labeled as for show missed reminders for writable kalanders Try to enable that function to use it again it is right ,that it might went turned off by the last update of this year that is used. Now

Greetings googlethunderbird.

Thank you for your help.

I had same issue after update, "Enabling missed reminders" got my notifications working again. Thanks!