Mitsubishi Electric MELSEC Q Series Reference Manual page 564

(2) When a programming tool connected station is faulty
Control station
No.1
Network No.1
Normal
Selected
station station
No.4
Set to the network No.2
562
Normal station
No.2
Normal station
No.3
Select the own station.
Stations equivalent to the maximum number of stations that can be
connected are displayed due to a parameter error.
An error has occurred in the station No.4.
Click the error details button.
The Error Factor field indicates that the network No. of the station No.4
has been set incorrectly.
Take corrective actions according to the troubleshooting.