no videos or images are visible

Hi, i’m having problems with bp attachments.
i post an image or a video but it doesn’t load and therefore it’s not possible to see it in the activities…. or rather… the activity is visible but without the video or image.
i tried with a different theme, turning off the plugins but nothing.
Any suggestions?

NB: Contact me privately to get the passwords of a test user

The page I need help with: [log in to see the link]