Several users have already reported error messages "SSL handshake failed error" shown when loading https feeds while indicating that the feeds loaded without SSL errors in their web browser.
I made some tests in my lab and it looks like this may result from corporate environments, in which the proxy is configured to perform SSL/TLS traffic inspection.
These companies typically use the internal root certificate authority to generate SSL certificates on the fly when users visit websites with https. The company root certificate is usually deployed in the windows OS certificate store, which explains why browsers like Chrome and IE can connect through https, and Firefox can't (it has its own certificate store, and the root certificate must be deployed in Firefox).
My question: where in quiteRSS can we add additional root certificates? (or: where does quiteRSS look into by default?)
You can delete the settings. Then they will be the default. The path to the settings "Help - About - Information"