RD Gateway not available due to firewall
I am running Windows Server 2016 Essentials. I am trying to set up Access Anywhere. I have set up everything, but when I run the Access Anywhere wizard, it gives me an error stating that the firewall is not properly configured. It says that my firewall is blocking Anywhere Access, and the problem can not be repaired automatically. I can access the sign-in page from the client, and then select a computer to access, but I get the error that the RD Gateway is temporarily not available. I run an online port checker, and it says that my port 443 is open. Seeing as the Access Anywhere web page is being accessed, then port 443 must be open, mustn't it? Turning off the Windows Defender firewall doesn't make a difference.. I get the same answer. I have an external firewall, but I have checked it and rechecked it. The settings are correct. All other traffic is coming through fine. What am I missing? How can I get this working?