In addition to what I wrote before, it looks like we can add a config setting to ignore certificate issues and index anyway.
We'll add that to the next version, but for now you can workaround it by calling this code from a plug-in.
ServicePointManager.ServerCertificateValidationCallback = ((sender, certificate, chain, sslPolicyErrors) => true);
(That's a static member).
To create a plugin, it's easiest to do it from the Index Manager tool's plugin page (it will create a template project for you)
https://keyoti.com/products/search/dotNetWeb/HtmlHelp6/UserGuide/Examples/Plug-in%20(Site%20Map).htmJim
-your feedback is helpful to other users, thank you!