Hi km276, please check your Internet connection. Perhaps it got cut off some time during the download, and this caused the error.
It may also help to disable your Antivirus and/or firewall temporarily before you try downloading again, as some antivirus and firewalls do cut off connections automatically especially when a download has been going on for too long.
If those tips don't help, please refer to the email that we just sent you from our support helpdesk (support ticket #17327).