When I open my Thunderbird, the toolbar doesn't show a Thunderbird icon but the default unknown file icon. When I minimize Thunderbird, the icon is still present as open and there's no Thunderbird tray icon. The tray icon only shows when I get new mail. On top of that, my phone no longer receives email notifications because email considers the email known when the Thunderbird isn't minimized to tray icon. Here's the troubleshoot information from Thunderbird help https://dl.dropboxusercontent.com/u/153845/troubleshoot%20info.txt Edit More info: when I unpin Thunderbird, the Thunderbird icon comes back but it still won't minimize to tray icon. When pinned on toolbar, the icon reverts to default file icon.