Error code: ERR_IO_NETWORK_ERROR 
- Wrong connection of 0.5M LAN cable between motion controller and IO board
- Defect in the LAN cable which connects the IO board and motion controller.
Machine components overview (Machine shown below is MAXX-5Z)
How to fix the issue:
a) Remove the rear cover of the machine. Disconnect the IO board LAN cable and connect again.
b) Unplug the connector and remove 4 screws to remove DC fan bracket.
c) Please check if cables are connected properly. Disconnect and connect again to make sure they are well connected.
d) Please try to use machine. If this error occurs even if cables are connected properly, then IO board LAN cable must by replaced.