I got 1.1.1 working by doing this:

1. Uninstalled everything browser-related from application manager
2. Removing directory /home/user/.mozilla/microb
3. Poweroff the phone and turn it on, to get browserd generate new ~/.mozilla/microb (sudo reboot nor any other kind reboot didn't work)
4. Installed 1.1.1 from xpi founded from site mentioned many times in this thread.
5. Add your favourite blocklist url
6. Poweroff the phone and turn it on again for sure, even MicroB says AdBlock is in use.
7. Check does it work and if it does, you can reinstall what you uninstalled (excluding AdBlock -package).