Which version of Gemini (web app) are you running? Do you have a valid certificate for the site?

I have self signed certificate for testing purposes.

Gemini 4.0

It is probably because of the self signed cert. Check in fiddler the response from the server.

Is there an app setting to trust all certificates ? if not, can it be added ?

Is there source code for Gemini 4.0 released ?

Yes, the source code for 4.0 is released to source code licensees. We don't have an app for certificate testing. Why not try it first without https?

It works without the HTTPS.

I was referring to some app.config setting that would just trust all certificates without validation. Something like:

System.Net.ServicePointManager.ServerCertificateValidationCallback += delegate { return true; };