Exactly the same happened to me. WD Mycloud, not home, but same firmware version.
The device is now blinking blue since 24 hours. Searching the net, it means a lengthy fsck takes place. I believe that is nonsense.
I think they bricked our device. I tried several resets to no avail. The device is also not pingable, which means: the network is not running and no outside access is possible.
My solution: I ordered another NAS already. From another company of course.
I hope you have a good backup!
I have been having the same problem with my 8TB unit. WD bricked our units and have locked us out of our data. I have had the blinking blue light for 6 days now. Is WD going to have a fix for this?
The 8TB unit I have I purchased on May 29, 2016. According to the serial number lookup, it is out of warranty–how convenient for them. Anyway, I have initiated the warranty return process. They are supposed to respond within 48 hours. I hope this won’t be a long protracted process. The bugs are in their firmware update V04.05.00-327. Based on their response, I may never purchase another WD product again.