There’s a rather long-lived bug in Xubuntu that will prevent a normal user from running the network manager applet (nm-applet), causing the network manager icon to go missing. Checking to see if you are experiencing this exact bug is pretty easy – just open up a terminal window and try typing nm-applet, then press Enter. If this is the bug you’re facing, you’ll get an error message about a failed network connection to a socket. To make extra sure, try typing sudo nm-applet, pressing Enter, then typing in your password at the prompt and pressing Enter again. This time you should see it pop up in your indicators in your panel.
In your terminal window, type:
sudo nano /etc/xdg/autostart/nm-applet.desktop
Press Enter, type in your password, press Enter again. You should now see a window called Nano that looks like this:
Go down to the line that says Exec and change it from nm-applet to dbus-launch nm-applet. Then press ctrl+O (which saves the changes), press Enter, then press ctrl+X and press Enter again (which should close out Nano).
Open up the Task Manager application, find nm-applet in the list, and if it’s there, kill it.
Now you should be seeing the network manager applet appearing in the indicators on your panel. 🙂