Some fault codes can be cleared by doing a Special Boot.
To do this simultaneously press and hold the 4, the Stop, and the Power Save buttons on the Control Panel while switching on the power. Hold the buttons down until the boot up screen (progress bar) appears.
And if did not work you can try with 1 or 6 instead 4 button.
And if still not working it is obviously you need a tech to reload the softwre or even to replace parts ( MCU board for example ).