Main menu lists are missing

When you put your mouse cursor over any of the main menu items, you should get a list/drop down menu:

If you ever hover over the main menu (Search, Add/Edit, etc.) and the menu lists do not appear:

Go to the top right corner, click on your initials/photo and then click My Settings:

Go to the Personal Information section and click Enable shortcut links on main menu tabs:

Click OK on the popup message:

The menus should be back to normal now.