Thanks for an essential fix! Rated 5 out of 5 stars
I still can't believe the Thunderbird devs think it's okay to blow up essential extensions WITHOUT EVEN ASKING. Especially since the upgrades are super-sneaky. I open my Thunderbird one day, and the calendar is gone -- poof! -- and the subject headings are back to the usual useless people send. (Stuff like "stuff," so I'd have to open every email to find out what's in it.)
Getting into about:config and setting compatibility to off for each picayune little version number gets real old, too.
Without this extension, the devs make Thunderbird just about worse than useless.