Even though I have no troubles connecting to the above listed addresses when using the editor, I was unable to successfully ping any of those listed IP addresses which means that Amazon has pinging its network disabled, which is unfortunate for our troubleshooting case.
In this case, the only way to check if this is indeed the cause of your issue, you would need to be able to have access to your network’s router settings as well as have administrator privileges to check your Windows firewall (or any other firewall software you may have installed) on your computer.
The latter is the easiest to check, assuming you have admin rights, since you can simply turn off Windows firewall (or any other firewall software) then try to open the editor again and see if you are able to login at that point, which tells you that you need to make some exceptions to allow traffic. If you are on a work PC, even if you have admin rights, your company’s network guys probably won’t be happy about you doing that, just as a fair warning.
As far as checking your network settings, if you are trying to connect on a computer that is on a company network, it would need to be configured to allow traffic in the above listed IP range as well. Basically open up the IP range of 18.104.22.168 to 22.214.171.124 for port 443 on a TCP connection.
That being said, after some more digging I came across this page:
which confirms what I found in regards to Amazon’s authentication. Further more, if you follow the AWS IP Ranges link on that page, it will bring you to a link to:
which gives us the entire range of IP addresses that amazon uses, including the range I listed above.
As far as Amazon needing to fix this, I do not believe anything is broken with the editor, nor do I believe what you are experiencing to be a bug. I do, however, think it would be nice to have an offline mode to the editor.