Julia 1.3.1 cannot automatically install

Are you behind a corporate proxy by any chance? It is possible that this issue affects you.

(As you also mentioned this in your other post), please, please do not do this anymore. You are putting your company and its customers’ data at risk and they will hold you accountable if anything happens. Your computer is about to execute software that you download over that connection, and you don’t want it to be replaced by malicious content.