My Cloud can't be accessed after updated to OS 5

I have successful updated my clound to OS 5 and loged in it, it seems good. but after a reboot, it never works again, it can’t be accessed from anywhere, Windows network, Windows local IP to admin, or web login, nothing comes out.
Please advise.

By the way, when I open Windows explorer, I can see WDMyClound in Storage of Network, and WDMYCLOUD in Computer of Network, but when I click on it, it shows “Windows can not accesse \WDMYCLOUD” after long time seeking.