https://askubuntu.com/questions/441730/no-system-tray-detectedSteps to follow for the complete solution of this annoying problem:
From the terminal run:
sudo nano /etc/xdg/autostart/hplip-systray.desktop
Add one # character at the beginning of the line: Exec=hp-systray -x (If you have HPLIP continue reading.)
Save the document and then open the "startup options" (one click in the Ubuntu wheel and search for the specific line).
Edit the HP System Tray Service.
Change that command with hp-toolbox.
Save changes and restart the computer.
outra solução
just deleted the file
/etc/xdg/autostart/hplip-systray.desktop
caso use o gnome ou cinnamon et etc...
Outra solução é colocar um tempo de espera para iniciar o aplicativo
no arquivo desktop adicione
X-GNOME-Autostart-Delay=30
ou utilize o comando sleep
sleep 30 && aplicativo
no arquivo desktop