The ESPCI kit assume a site hierarchy that is compatible with internationalization: the site root must contain a section for each language (
Accueil for french,
Home for english and so on), each translation of the site must be nested in that root language sections. Please modify your site hierarchy to get compliant with this constraint (this will remove this message). If you want to create an english-only site, create a
Home section at the root, and move all your site inside it.
Link to the complete documentation (in french).
ESPCI web site
