Hello, If you're talking about the X-Notifier extension/add-on, the purpose of which is to show you your number of unread emails, it is possible that it is unpinned. A pinned extension shows up in the toolbar, at the "very top right" like you describe. If you wish to pin this extension, follow these steps: * Hit the "Extensions" button on the top right next to or near the Menu (☰) button. It has a distinctive jigsaw puzzle piece icon shape. * Find the extension you wish to pin. In your case, that would be the X-notifier add-on. * Right-click the extension, and click "Pin to Toolbar". You should notice that it takes a place next to the Menu (☰) button now. If the extension is not listed, [https://addons.mozilla.org/en-GB/firefox/addon/xnotifier/ install it here], or click "Manage extensions" at the bottom of the list, scroll down, and re-enable the extension (it won't show up if it's disabled). This could be an issue with the extension itself, in which case, you can only contact the developer about your issues. Cheers,