Hello, a while ago I updated Thunderbird, to verson 78.7.0 for Centos 7. Lightning plugin/add-on was uninstalled and Thunderbird could no find the calendar info (I guess that's lost). After another update, to this version, Thunderbird reports it cannot find the Calendar info, and basically crashes Thunderbird. There is an enable button in the Calendar tab, but is doesn't show anything So how do I use/configure (and hopefull restore) thee calendar function in thunderbird, (and possibly retrieve the old calendar info)? thanks, Ron