If you try to use a Plex.Earth function and you get the "Unable to connect to the remote server" error there is something blocking the connection with our servers, which is needed to perform all coordinate transformations.
If you are behind a PROXY SERVER, you can configures its settings in Plex.Earth's Options -> Connection. If the problem persists you can also try configuring them in Internet Explorer (Tools -> Internet Options -> Connections tab -> "LAN Settings") and then try the "Auto-detect" and "System Proxy" options (as shown below) in Plex.Earth's Options -> Connection.
If your FIREWALL is blocking the connection, you will need to set it to allow access to the following address:
px31-srv.plexscape.com (on port 80)
If you are still experiencing problems, please contact us directly at firstname.lastname@example.org.