How can I install Check4Change manually?


Firefox 45 introduced a new security feature called "add-on signing". The FireFox team manually reviews each add-on and signs it after it checks it's not malicious. link
While this feature is generally an important security enhancement, it also means users can't install an add-on directly from an author they trust, and instead must wait until the add-on is approved by FireFox.

If you are in a hurry to install the latest Check4Change version and don't want to wait for the review process to finish, you must disable add-on signature checking:
1. Go to about:config (enter it into address bar)
2. Set xpinstall.signatures.required to false.

Afterwards you can install the latest version of firefox from here.
Once the add-on is available from FireFox you can re-enable "add-on signing" and install Check4Change directly from FireFox.