Unable to configure Plex on WD My Cloud Home

I got a brand new WD My Cloud Home. I cannot configure Plex on Windows. After enabeling Plex I choose Configure.
Then I get the message that “wdckeystone.com is currently unable to handle this request”. HTTP error 502.
And please don’t give the answer to go to:
Followed all the steps, no results. Same error occurs over and over.
Any idea how to solve this?

Received an answer on my support question.
What worked for me is that I opened Plex in my webbrowser and signed in to Plex.
Then I choose “Configure” Plex in My Cloud Home and it opened the settings for Plex.
Enabled DLNA in Plex and now I can stream music to my Yamaha network receiver.
This is the answer I got from WD-support: