Users with the
upload files permissioncan upload attachments. Users with the
view uploaded files permissioncan view uploaded attachments. You can choose which post types can take attachments on the
content types settings page
Above is the help text from files upload admin settings page (admin/config/media/uploads) were the highlighted texts are links. The last link
content types settings page is broken.
In upload.module line 21 changing
'@types' => url('admin/settings/types') to
'@types' => url('admin/structure/types') will fix it.