A few days ago, while I was doing some network configuration tests, I went offline.
At first I did not realize, but all indicators (cpu, memory, ...) even the one of the network manager disappeared from the top panel...
Using a USB live, I reinstalled network-manager, but I'm still unable to see the icon.
The indicators are also running, but they're not visible (same as the network manager).
How can I get them back visible in the top panel?