I don't want to know how many browsers do not verify #XPI signatures anymore... Like zombies, walking around
If you disabled xpinstall.signatures.required make sure you reenable it now! 
And pass this reminder on to your peers and channels
@martin moz has fixed it now?
Follow
@absturztaube since version 66.0.4 on Desktop and Android, and version 60.6.2 for ESR
https://blog.mozilla.org/addons/2019/05/04/update-regarding-add-ons-in-firefox/
