Windows Server 2008 vagrant box running but unable to add remote Ruby SDK in RubyMine Follow

I'm running RubyMine on macOS High Sierra 0.13.3 (17D47), and I have a Windows Server 2008 R2 SP1 Vagrant box which is running that I can SSH into (Microsoft's implementation of OpenSSH) fine.  I'm not using keys.

When I try to add the Remote Ruby SDK location in RubyMine is gives me an SFTP error.  Or, if I try to change the Ruby bin path it gives me an error.  On Windows, my Ruby bin path is C:\Ruby21-x64\bin not /usr/ruby/bin.  Here's the error:

Vagrant file:

Vagrant.configure("2") do |config|
  config.vm.box = 'windows-server-2008-r2-sp1'
  config.vm.guest = :windows
  config.winrm.timeout = 500
  config.ssh.username = 'vagrant'
  config.ssh.password = 'vagrant'
  config.ssh.insert_key = false
  config.vm.network :forwarded_port, guest: 80, host: 8080
  config.vm.network :forwarded_port, guest: 5985, host: 5985
  config.vm.network :forwarded_port, guest: 1433, host: 1433
  config.vm.network "private_network", ip: "192.168.33.10"
  config.vm.provider "virtualbox" do |vb|
    vb.gui = true
  end
end

vagrant ssh-config:

Host default
  HostName 127.0.0.1
  User vagrant
  Port 2222
  UserKnownHostsFile /dev/null
  StrictHostKeyChecking no
  PasswordAuthentication no
  IdentitiesOnly yes
  LogLevel FATAL