Steps to reproduce:

1. Create a clean eZ Studio installation;
2. In the backoffice, go to Admin Panel / Languages, and add the language "en/en" (i.e. enter "en" in both "Name" and "Language code" fields and publish). You should now have 2 languages: "eng-GB" and "en";
3. Edit /app/config/ezplatform.yml and add the new "en" language:

ezpublish:
    ...
    system:
        ...
        site:
            languages:
                - eng-GB
                - en

Note: clear symfony cache afterwards so that the changes take effect:

php app/console cache:clear

4. Create a new landing page e.g. <Test> under the <Home> node and change the language from "English (United Kingdom)" to "en" by clicking on the "change" link on the top-right corner;
5. Publish;
6. Click on the Page menu (eZ Studio), then Edit.

Expected behavior:

• On the right pan, Basics tab, the Page title and Page description are filled with values entered in step #4.
• The central pan displays the zone area in which I can drag & drop Block elements.
• When I click on Publish, the message "content well published" is displayed and the content is saved in the selected language.

Actual behavior:

• On the right pan, Basics tab, the Page title and Page description are not filled with values entered at STEP#4 and remain empty.
• The central pan do not display the zone area in which I can drag & drop Block elements.
• No action is triggered when I click on Publish.