I doubt anyone here would have any use to know about this, but Unity 2019 doesn't recognize the newer Let's encrypt certificates, or at least PC VRChat doesn't.

I doubt anyone here would have any use to know about this, but Unity 2019 doesn't recognize the newer Let's encrypt certificates, or at least PC VRChat doesn't. That is why you cannot use Let's encrypt certificates when serving any content to PC players with HTTPS. What is really fun is that because of a certain type of content hosting world in VRChat, a lot of people have manually installed these old certificates in Windows which makes it incredibly annoying to troubleshoot unless you know about it. While it sure wasn't fun to try and troubleshoot that, I still very much enjoyed what I was doing. When you get into the creating side of VRChat you learn a ton of specific stuff and you are forced to work around some really narrow limitations and that is so fun.