How does your language settings look on the root page in CMS?

The settings in the web site config section is also interesting to see

If you're building a multi-lingual site then all your languages should have a language component as this is a requirement for Optimizely to route into the correct language version of your content.  You could look at overriding the routing behaviour, but I wouldn't recommend it and I would consider what this means in terms of consistent behaviour of URLs and SEO.

I have following settings:

and

In this solution there will be several StartPages for the same host that are in "Norwegian Bokmål" or "Norwegian Nynorsk".
The thing I would like to achieve is that if I use the url www.site.com/abc then it will show the page with the url www.site.com/nb/abc if the page abc is having the language "nb" as its master language. So both url's should work.

Hi Robert,

You can do the following in appsettings.json

"EPiServer": {
        "Cms": {
            "RoutingOptions": {
                "StrictLanguageRouting":  false 
            } 
        }
}

This will assume the primary language can be served without the language component.  The canonical URL will still render with the language component, but it's best checking with your SEO team what this impact will have as you run the risk of search engines flagging your content up as duplicates and potentially harming your SEO ranking which could be bad.

If you want to get rid of the language segment, then you just need to map a host to a culture in your site settings.