I get this error on the webpage when I switch to another language in the admin area, in this case German (de_DE). I have to delete the language files via ftp in order to access the admin area again and switch it back to English:
The website encountered an error while retrieving xxx.xxx. It may be down for maintenance or configured incorrectly.
I have a working version of the install on my localhost where I can switch the admin language without issue. I used the plugin "Duplicator" (http://wordpress.org/extend/plugins/duplicator/) to clone the package and upload it to my webserver to test it at, for example: "mydomain.com/wordpress".
Everything else works fine, permalinks, page links etc. but when I switch the language to German it gives me a error message as above.
What could be the issue here!?