“Fatal Error” are issues occurring during loss of communication events.
In order to drive the Epson printer and especially the measurement device, constant latencies below 1ms are required. 2 or 3ms are usually OK but any ping time beyond that, indicates insufficient quality of the connection between printer and PC to ensure a stable operation.
The solution would be to try and improve the connection quality. If both the printer and PC are close to each other, try connecting them via a dedicated network cable, to take the switches, patch fields, cables attached to wall ethernet ports out of the equation.