[Geschlossen] Changing URL for languages

Background of the issue:
I'm trying to change the language URL on our test server new.grontkontor.dk, but I encounter errors. The issue can be seen at the following link: versteckter Link.

Symptoms:
I expected the URL to change to domain names instead of directories, but instead, I got errors for all languages.

Questions:
How can I change the language URL to domain names instead of directories?
What might be causing errors for all languages when attempting to change the URL?