You can check the home page setting to see if the about:preferences page is appended (|about:preferences#general). *Tools > Options > General > Startup: Home page *https://support.mozilla.org/kb/How+to+set+the+home+page Firefox supports multiple home pages separated by '|' (pipe) symbols. ---- This can happen if you click "Use Current Page(s)" to set the home page. You can pin the tab with the about:preferences page to prevent including about:preferences to the home page setting if you want to use this button. To set a single page as the home page you can drag the globe/padlock to the toolbar Home button.

yes got it thanks man