I'm trying to get GOG Galaxy going for the first time, and I get two login screens: first email and password, then my username shows and I'm prompted again for my password. It starts loading then bounces back to that second screen. I did some digging in the logs and found in the GalaxyClient.log:
A problem report reply had an SSL error, Qt SSL error codes '10 (The root certificate of the certificate chain is self-signed, and untrusted)'.
Failed to send problem report 'launching_updater_failed (type client_self_update_failed)'. The server replied with 6 (SSL handshake failed) and the HTTP status code <NULL>.


Any thoughts? insights? solutions?

If your security software has an "SSL scanning" feature, make sure it's disabled.

In case the error message is misleading, it's also worth trying the following:
• Double check that the GOG Galaxy executables are allowed Internet access. They're located in both C:\Program Files (x86)\GOG Galaxy\ and C:\ProgramData\GOG.COM\Galaxy\
• Disable IPv6 and restart your system.
• Set your DNS to Cloudflare.