I tried to add the latest norwegian language pack to my clean newly installed e107 v1.0.1. This caused the site to go white, both frontend and backend.
There was no error msg of any kind given. The languagepack was added after the site was installed, and uploaded through ftp.
Run the e107 debug browser addon to retrieve the error message. Obviously its related to the language file but when we see the error we can exactly pinpoint the issue instead of taking multiple guesses
You can also add ?[debug=all] at the end of your url, to display the debug info. Scroll down and find errors and warnings.