@Zheng-Han You are right - it's my fault. I simply didn't read the full article.
I clicked immediately on http://omega-xxxx.local/ without these steps:
opkg update
opkg upgrade base-www
opkg install onion-os

Do make sure to let us know what you think and if you have any ideas on how we can make it even better! / @pavel-metrokhin /

There is a (misleading;) green lock in the login box but the full stuff operates on http (ie. insecure). Am I wrong?

I don't use Onion's web based Console but I'll try this new one surely. :-)