Hi, could you explain where you see this problem? Is it in a pop-up message from your security/antivirus software, or in a tab of a page Firefox trying to load, or somewhere else? If you think your Firefox might have a rogue add-on installed, try starting Firefox in its Troubleshoot Mode. In that mode, Firefox temporarily deactivates extensions, hardware acceleration, any userChrome.css/userContent.css files, and some other advanced features to help you assess whether these are causing the problem. Here's how: ''If Firefox is running:'' You can restart Firefox in Troubleshoot Mode using either: * "3-bar" menu button > Help > Troubleshoot Mode... * (menu bar) Help menu > Troubleshoot Mode... and OK the restart. A small dialog should appear. Click the Open button. ''If Firefox is not running:'' Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.) A small dialog should appear. Click the Open button. ''Note: Don't use the Refresh without first reviewing this article to understand what will be deleted:'' [[Refresh Firefox - reset add-ons and settings]]. ---- Next, check your home page and new tab settings, and review your extensions: (1) [[An extension changed my New Tab page or home page]] (2) You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either: * click the Extensions button (puzzle piece) on the toolbar > Manage Extensions * Ctrl+Shift+a (Mac: Command+Shift+a) * "3-bar" menu button (or Tools menu) > Add-ons * type or paste '''about:addons''' in the address bar and press Enter/Return In the left column of the Add-ons page, click Extensions. On the right side, find the "Manage Your Extensions" heading. ''If there is at least one extension before the next heading -- "Recommended Extensions" -- please continue:'' Then cast a critical eye over the list below that heading. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious or that you just do not remember installing or why? If in doubt, disable (or remove). For your privacy and security, don't let mystery programs linger here. The next time you start Firefox normally, any improvement?