If you need the previous version of AdBlock Plus for Firefox, check out the app's version history which includes all versions available to download. While the developer is fixing the problem, try using an older version. Sometimes, the latest version of an app may cause problems or not even work. It will automatically detect the platform and language on your computer and recommend the best version of Firefox for you.
Visit the in any browser (for example, Apple Safari).
If you use an old version of OS X, see this article for more information. Make sure your Mac meets the for Firefox.
