I have an annoying issue. When I open from start my Firefox browser, it always opens two tabs. One says New Tab the other one says Installation Succesful. To get onto the browser I have to swap to new tab. The Installation Successful relates to something to do with Adblock Plus see: moz-extension://3cb4d606-8343-4933-983b-aa3b8ea8719a/first-run.html I want to stop this from happening but cannot figure how. Any advice please ?