After upgrade the FW and my cloud can’t link. someone meet this issue?
Here is troubleshooting steps that you can try:
Confirm the network cable is properly connected to the WD My Cloud Personal Cloud Storage device and the network switch or router.
Make sure the network switch or router has power.
Use a different network cable and port on the network switch or router. Temporarily swapping the WD My Cloud device’s cable port with a working network device may identify any failing cables and ports.
Checking back panel (network) LEDs, both Activity LED & Link LED apperance Off.
If still the issue persists, you should try contacting WD Support from the link given below.