Default language
The default language for block and notification pages is English. You can change this by selecting a different language from the Default language drop-down list.
If you select a different default language and then click Save, your changes are immediately visible to end users. Ensure that you have saved pages in the new default language; if a page is not available in the new default language, the English page is displayed.
The end user registration pages for secure form-based authentication are already available in the following languages: French, German, Italian, Dutch, Spanish, Simplified Chinese, and Japanese.
See Language support.