EVERYONE WHO CAN'T INSTALL- Download the latest version of Firefox, 66.0.5, from google play etc, or apkmirror. Voila, it's fixed. This is a problem with the last version of Firefox, with all addons, not the addons themselves.
uBlock Origin is the best, but it is impossible to upload it on Mozilla Firefox again, that make using it impossible too. "Download failed. Please check your connection". My connection is ok. What is going on with Mozilla? Please, help.