I've applied some fix in following file in your site and temporary turn on development mode from your Easysocial backend in order to make it work now.
JoomlaFolder/components/com_easysocial/themes/wireframe/story/photos/plugin.js
JoomlaFolder/media/com_easysocial/scripts/site/story/photos.js
After we release new Easysocial version end of this week, you can turn back to production mode, you can refer on my attached screenshot below.
Regarding with your email subject not get translated to French issue :
>> I've help you uncomment those language constant from this language file
JoomlaFolder/language/fr-FR/fr-FR.com_easysocial.ini
; COM_EASYSOCIAL_EMAILS_EVENT_GUEST_GOING_SUBJECT="{actor} will be attending {event}."
; COM_EASYSOCIAL_EMAILS_EVENT_GUEST_GOING_TITLE="%1$s will be attending %2$s."
; COM_EASYSOCIAL_EMAILS_EVENT_GUEST_GOING_CONTENT="This is a notification to inform you that %1$s will be attending %2$s."
Replace to
COM_EASYSOCIAL_EMAILS_EVENT_GUEST_GOING_SUBJECT="{actor} will be attending {event}."
COM_EASYSOCIAL_EMAILS_EVENT_GUEST_GOING_TITLE="%1$s will be attending %2$s."
COM_EASYSOCIAL_EMAILS_EVENT_GUEST_GOING_CONTENT="This is a notification to inform you that %1$s will be attending %2$s."
it should work fine now, you can refer on my second attached screenshot below.