Developer reply by Itagaki Fumihiko
Rated 5 out of 5 stars
Love this add-on, but in the latest version of Thunderbird (91.10.0) it no longer works correctly. like some other add-ons. I should turn the add-on off and then turn it EACH time I open Thunderbird.
Ok, disabled all other add-ons and then enabled them one by one, checking which one caused the problem and the problem is caused by: Phoenity Icons
So have disabled that one, until it will be fixed.
Please try to disable all other add-ons.
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