Have you came across this popup when you’ve tried to download something?
Then, you might be using a public computer that restricts downloads and other firefox settings.
But don’t worry. That’s very easy to hack.
All you need to do is Open Firefox in Safe Mode.
If you’re in Windows, just press the Shift Key and run Firefox.
In Safe Mode all add-ons doesn’t run.
Congratulations! You’ve just hacked public fox add-on!
Download all you want!