It seems like over the past several months that every time there's an update to Thunderbird, it totally messes up the Lightning calendar. I really like the Thunderbird product and when everything is working with Lightning, it really works well with our accounts hosted on Gmail. However, after the last update I wasn't able to link in an employee's calendar for weeks because it wouldn't work with the new provider for Google Calendar and Lightning. After a month or longer I finally tried it again and it started working. But now I just installed an update to Thunderbird for 31.5.0 and now 1 of the 3 linked calendars I have won't work. It's getting to be really frustrating having to waste time trying to get this working again, when it was working just fine before the update.