In the launcher bar, there are "icons" that display a text ("System Settings," "Home Folder") when you float the mouse over them, but they're just black -invisible – it looks like a blank spot between the other icons, but… they work!
This is also true when I open the system settings window – I can see some icons, but others just have text that disappears into the white background when I go to click on them (they also work, but it's just sorta weird…
Ubuntu – “invisible” icons in the launcher bar
iconslauncherunity
Best Answer
Try changing the theme in System Settings > Appearance. You should immediately see the results.