This was the exact text they gave me:
Would you please check in the installer options to ensure that you do not have any text in the proxy section?
I don't have the installer in front of me, but I think in the first screen there is a "settings" or "options" button, maybe in the top right? That has a bunch of settings including a network proxy setting. Unless you have a network proxy, you want to make sure it's blank.
In my case, that field almost LOOKED blank -- it had a backtick character in it, which was really hard to see. Deleting that character and saving the options fixed it.
Good luck, please let me know if it helps.