First of all, please update the server and all workstations to the newest build.
You can download the installer file from your account at https://clients.translation3000.com

Then, you and the remote user will need separate user accounts. Create (if you haven't already) a user account for the other user in the "Administrator >> Users and access" screen of your Workstation.

Next, after installing the Workstation on the remote user's machine, make sure that the connection parameters are correct: Click "Server" in the login dialog. Select either LAN or Internet and enter the server's address.

If you encounter a "port 212 is closed" error, make sure that the port is open the server's firewall.