title: psycopg2.OperationalError: FATAL: unsupported frontend protocol 1234.5679: server supports 2.0 to 3.0
body: <p>I'm using Macbook</p>
  
  <p>Psycopg2 works well when connecting the localhost db (PostgreSQL on Mac). The error was raised when I tried to connect PostgreSQL db on a Windows10.</p>
  
  <p>the following code is what I have for connection, the host is just the IP of the windows10
  </p>
  
  <pre><code>db= psycopg2.connect(database='dbname',user='username',password="secret",host="192.168.3.9",port="5432")
  </code></pre>
  
  <p>Errors: </p>
  
  <pre><code>  File "path/to/psycopg2/__init__.py", line 126, in connect
      conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
  psycopg2.OperationalError: FATAL:  unsupported frontend protocol 1234.5679: server supports 2.0 to 3.0
  </code></pre>
  
  <p>Is this because of system compatibility or something else? I've tried other Windows machine and I got no luck to make it work.
  However, I was able to connect PostgreSQL on windows while I using  <a href="https://www.npmjs.com/package/pg" rel="noreferrer">Node.JS module pg</a></p>