Missing translations for library core

Hi,

I use Drupal plugin of h5p for some time now without problem. I updated it from rc14 to rc16 and got this error message on the hub with hub not loading : Missing translations for library core.

Link to the thread on drupal website : Missing translations for library core

I tried to revert to rc14 but still got this message. All translations are up to date on my site (french language).

Help pls

Attachments: 

Hub is back with rc12 : more recent versions are not working (i think there's a problem with the language switch fonctionality).