Rated 1 out of 5 stars
Thunderbird 60.5.0, Lightning 6.2.5, Provider 4.4.2.
**STILL** cannot dismiss meeting/calendar events and alarms. Tried to dismiss a single item, or ALL past ones. Nothing works, and my only option is to completely disable Lightning and Provider, otherwise there will permanently be a non-closable window showing passed events for the past two months or more. I am stuck using a Google Chrome window for my company calendar (Chrome, yech).