When trying to Select Data I am getting an error message "Your connection is not private". Any ideas what's wrong?

I’m using Chrome on a Mac. The error says: “Your connection is not private. Attackers might be trying to steal your information from usa.ipums.org (for example, passwords, messages, or credit cards). NET::ERR_CERT_AUTHORITY_INVALID.”

I restarted my computer and that fixed the problem. Thanks!