Efficace et silencieux

I like this add-on. It's really useful. But, lately I've been having some stability issues with it. Like, it'd open a tab saying "thank you for installing" everytime I open Firefox. I also have to restart firefox everytime I try to restore the session from my last usage. It's kind of annoying. I'd really appreciate if you could fix it and make it work properly.

When about youtube i had to click the skip button

other works properly