Protocol remains HTTPS on redirects to HTTP on port 80
When downloading Java from "www.java.com", the user is forwarded to "http://www.java.com:80/en/download/[..]" but HTTPS Everywhere changes "http" to "https" and keeps the part about ":80" which breaks the redirect.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information