Rated 5 out of 5 stars

It was a great add-on until a recent update. Now it no longer appears in Thunderbird. It is listed in the list of Add-ons, but it says that it will be installed when Thunderbird is restarted. Well, I restarted Thunderbird several times and still it is not working, although sometimes Thunderbird does not even appear, so maybe it's a problem with Thunderbird. Any ideas?

This review is for a previous version of the add-on (1.9.9.2).