Error to connect PLC KV8000 OPC UA

Hello everyone,

I tried to connect my Keyence PLC model KV8000 in the way mentioned in the following link Connecting Ignition to Keyence PLCs using OPC-UA | Corso Systems , but I get this error.

Does anyone know if I need to have my port 4840 open, or if there is another firewall configuration I need to set up, or if the problem is something else?

Thanks.