With the new upgrade to mediawiki 1.26 and its extensions, the notifications' layout has changed. For now, there is no more the grey alert button on the top bar, but it is placed inside the popup menu which is opened once the user clicks on his name. What is need to be done is to restore the layouts like it was in the previous version. That is, the grey button with the bell must be aligned aside from the user name. Furthermore, there is another button that is activated only when user gets at least one message.
This new button should be placed alongside the alert button