First thought that crossed my mind was whether the langues are enabled at all?
It could be a routing issue? if you have a legacy project. See http://world.episerver.com/forum/developer-forum/-EPiServer-75-CMS/Thread-Container/2015/3/localization-not-working/
Hello, i have an issue when i change the language(lets say i go to my site/de from my site/fr ) where even though the url changes the language doesnt change and the CurrentPage.Language remains the same(fr instead of de even though the url is now with /de). I tried debugging but i have a feeling its either a setting or something of sorts. Any ideea what might cause it or what i should look for?.