I keep getting an error

If the message you are getting says the internet is down, I assume that is the problem. Without a proper working internet, it is not possible to do successful downloads of any kind. Are you otherwise able to access the internet? The first step is to check your internet to see if it is working. What is your connection? Wi-Fi or Ethernet. Do NOT use Wi-Fi for these downloads. it is too slow for these very large files. Do you have anything else connected to the internet that is working? Here are some troubleshooting suggestions. Restart your modem. See if that changes anything. That resets the modem. Next, visit your internet provider's web site. There they usually have links to diagnostic tools which can check and confirm your internet's connection. If it is bad, then they can help you to get it fixed.

Update or upGRADE ? What is being downloaded ? Please put this in context as we are guessing.