You have configured an HTTPS certificate in Home Assistant. This means that your internal URL must be set to a domain covered by the certificate

When changing the local network URL in https://192.168.178:8123 I get the following message:

Invalid local network URL

You have configured an HTTPS certificate in Home Assistant. This means that your internal URL must be set to a domain covered by the certificate.

I don’t want to use a reverse proxy like Duckdns because I want to make sure that I can still reach my Home Assistant in my local WLAN if the internet goes down, but I am still connected to my router.

Does anyone have any ideas?

IPv4 addresses ar Number.Number.Number.Number:Port you are missing a Number.