Ubuntu – Missing indicator/tray icons (Steam, Chrome, Dropbox, etc)

gnome-shellgnome-shell-extensionindicator

On my installations of Ubuntu 18.04 and 18.10 all the indicator icons from Chrome, Dropbox, Ulauncher, InSync and Steam are missing.
These are the indicator currently installed:
enter image description here

And these are the Gnome extensions installed:
enter image description here

Looking Glass shows no error for the gnome-shell-extension-appindicator:
enter image description here

Best Answer

The problem was having Unity and its indicators installed. After removing completely Unity and all its indicators the icons are back:

enter image description here

This is the list of the package with "indicator" in the name you should have installed:

$ apt list --installed | grep indicator    

gnome-shell-extension-appindicator/cosmic,cosmic,now 22-1 all [installed]
libappindicator1/cosmic,now 12.10.1+18.04.20180322.1-0ubuntu1 amd64 [installed,automatic]
libappindicator3-1/cosmic,now 12.10.1+18.04.20180322.1-0ubuntu1 amd64 [installed]
libindicator3-7/cosmic,now 16.10.0+18.04.20180321.1-0ubuntu1 amd64 [installed]
libindicator7/cosmic,now 16.10.0+18.04.20180321.1-0ubuntu1 amd64 [installed,automatic]
Related Question