5 つ星中 5つの評価を受けています

投稿者: Firefox user afa19a - 12月 5, 2017 · 固定リンク

Due to changes in the Firefox API, this add-on cannot be made compatible anymore for Firefox 57 and above. Best alternative is to reinstall Firefox 56 and to disable automatic updates.

https://www.wikihow.com/Downgrade-Firefox