Installation stops at Onboarding

I am trying to set up Home Assistant on a Rasp Pi 3B. The process went successful, I could open http://homeassistant.local:8123 on my browser, but soon after it seems stuck on page http://homeassistant.local:8123/onboarding.html saying “Something went wrong loading onboarding, try refreshing”.
I can ping homeassistant.local, showing [fe80::120b:2041:efa1:b582%8]. Obviously, that is an IPv6-address. My router’s LAN-list does not show this address. Do I need an IPv4-address and if so, how do I get it? I tried PuTTY on fe80::120b:2041:efa1:b582%8 but that won’;t work either.

Solved by rebooting my router. Must have been a DNS-problem