Configure Windows Server 2016 Firewall for FTP

I just created a 'New Rule' - opening TCP 20-21 and got it working. Microsoft default FTP Rules were still in place and activated, but were blocking the connection.

When you install IIS, it preconfigures firewall rules in Windows Firewall.

You may just need to enable those rules to make it working.

Go to Control Panel > System and Security > Windows Firewall > Advanced Settings > Inbound Rules and locate three "FTP server" rules. Make sure they are enabled. For details, see my article on Installing a secure FTP Server on Windows using IIS.

If this does not help, you need to give us more details. Particularly, what exact problem/error message are you getting. "Is not available" is pretty vague.