Create a new folder activity and make sure the filepicker displays: "You can drag and drop files here to add them." Add a file and save your changes, then visit the folder page and make sure the file has been uploaded. Go to Settings > My profile settings > Edit profile, make sure the filepicker to upload your avatar displays: "You can drag and drop files here to add them." Select a file as avatar, update your profile and go back to that page to see if the avatar has been updated.