“invisible” icons in the launcher bar

Question

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...

Answer 1

Try changing the theme in System Settings > Appearance. You should immediately see the results.

Answer 2

Remove the invisible icon from the launcher

Launch the application from the dash. then while the application is open again search for the same app in the dash. Drag the app to the launcher bar afresh. You should now be able to see it.

Thats how I managed it, thanks to @vasa1 : Chromium Logo Invisible :)

Answer 3

In this answer I will give the example of xmahjongg available in the software center that gives this problem.

First look at the associated .desktop file for the application - desktop files are normally located in /usr/share/applications

[Desktop Entry]
Version=1.0
Type=Application
Name=xmahjongg
Name[bg_BG.UTF-8]=Маджонг (xmahjongg)
GenericName=
Comment=A colorful solitaire Mah Jongg game
Comment[bg_BG.UTF-8]=Премахване на купчина плочки чрез групирането им по двойки
Icon=
Exec=/usr/games/xmahjongg
Terminal=false
Categories=Game;CardGame;

Look at the Icon value - if it is empty as per xmahjongg then the desktop launcher icon will also be empty.

We need to give this an icon name.

Icons are stored in /usr/share/icons

For this example I looked in /usr/share/icons/hicolor/24x24. There are .png files in there. Pick-one and add its name (minus the .png extension) to the .desktop file

For example gnome-panel-fish

[Desktop Entry]
Version=1.0
Type=Application
Name=xmahjongg
Name[bg_BG.UTF-8]=Маджонг (xmahjongg)
GenericName=
Comment=A colorful solitaire Mah Jongg game
Comment[bg_BG.UTF-8]=Премахване на купчина плочки чрез групирането им по двойки
Icon=gnome-panel-fish
Exec=/usr/games/xmahjongg
Terminal=false
Categories=Game;CardGame;

Next drag and drop the icon from the Dash into the launcher to give you:

Obviously - pick an icon that aesthetically is appropriate for your application!

Note: if you make the icon change in /usr/share/applications then a subsequent update could overwrite the .desktop file. Its safer to copy the .desktop file from /usr/share/applications to your home folder ~/.local/share/applications.