Try a download, e.g. download Ubuntu 15.10 amd64 iso image from http://www.ubuntu.com/download/desktop/thank-you?country=DE&version=15.10&architecture=amd64.
Try a download, e.g. download Ubuntu 15.10 amd64 iso image from http:// www.ubuntu. com/download/ desktop/ thank-you? country= DE&version= 15.10&architect ure=amd64.