OK, another option is to use the GoToMeeting web app in Chrome: https://support.goto.com/meeting/help/what-is-the-web-app-g2m090016
I turned off Windows Defender Real Time Protection. This time the error message came back within 2 minutes, rather than running for nearly an hour. That seems like progress. It seems like it must be a permissions issue?
I read the GTM help on "How do I configure GoToMeeting to work with firewalls?" and particularly where it talks about "Open your anti-virus program to allow it to accept all GoToMeeting files." However the download itself is not a problem, it is with running the installer. So then I looked in "Allow apps to communicate through Windows Firewall" but I cannot see anything I can identify as GTM.
It seems odd to me that this could be the first time this has happened to someone trying to download the GTM app. The MSI approach is more than I want to mess with for now.
OK, another option is to use the GoToMeeting web app in Chrome: https://support.goto.com/meeting/help/what-is-the-web-app-g2m090016
