BuddyPress.org

I ran into a big problem with avatars: images could be uploaded, but the crop box couldn’t be adjusted (it could only be found up in the lefthand corner of the image), when you cropped anyway and went ahead the image literally bounced around the page, and the uploaded images wouldn’t show up — I’d just get a black box.

The solution, as it turned out, was to look for plugins that might be causing the conflict. For me, the Litebox plugin for WordPress was causing the problem — deactivating it enabled everything to work just fine.