Is there a specific port BeamMP uses that might be blocked, leading to error 10060, and how do I ensure it's open?

Yes, BeamMP primarily uses port 30814. This port needs to be open for both UDP and TCP traffic, especially on the server host's side through their router's port forwarding settings and local firewall. For clients, their firewall needs to allow outbound connections to this port. To ensure it's open, access your router's administration page, navigate to 'Port Forwarding' or 'Virtual Servers,' and create a rule to forward external port 30814 (both UDP/TCP) to the internal IP address of the machine running the BeamMP server. Also, ensure your operating system's firewall has an exception for the BeamMP server/client executable on this port.