R.I.P Firefox. Hello Opera!!!
And Mr akiha. Your solution
C:\Users\%USERNAME%\AppData\Roaming\Mozilla\Firefox\Profiles\[name].default\extensions
Is NOT working for Linux users!

PROBLEM SOLVED! For the time being.
https://www.ghacks.net/2015/06/19/how-to-disable-the-firefox-40-add-on-signing-requirement/
https://www.ghacks.net

Been using Ghostery since it first came out and am nothing but pleased with it. Great work devs.

Idiots stop giving the review one star just because firefox has a glitch.

I've been using another popular ad blocker (and still do) but recently I found that on certain sites they had code that wasn't being blocked, so I tried Ghostery, and it is blocking the ads the other one didn't! While I see no reason not to use both, I can definitely tell that if the other one ever stops working, Ghostery will have my back. :)