Device Reports "Unknown: write fail", WD My Cloud EX2 Setup Fails

I am still able to access my drive via AFP, however, I am not able to access it via WD Sync (Password is invalid), the web interface, or install My Cloud EX2 (as it crashes)

When I attempt to connect to the web-portal on the device I get the following:

Also I’ve attempted to install the latest version of My Cloud EX2, on OS X with all the latest updates, and it fails (without warning, and no message) the installer just closes.

I was able to resolve my issue with the web-login by resetting the device.

I am glad this has been resolved.