Had it myself for some time. Same exact error message. The cause was my /etc/hosts file. cat /etc/hosts | grep apple I had there: 0.0.0.0 gdmf.apple.com I don't have any idea how it got there, but it was there and it blocked my computer from reaching Apple servers. Commenting that 1 line resolved the issue for me. Make sure your computer doesn't block connection to gdmf.apple.com in any other way.