The battery level and some other icons disappeared from my screen. What should I do?
This, along with other random operational quirks can typically be resolved by shutting down and restarting the system.
1) Press and hold the power button until the prompt appears on screen asking if you wish to shut down.
2) Confirm you wish to shut down
3) After the machine is powered off, press and hold the power button until the two white LEDs flash on the right side of the system. The system should now restart and respond normally.