DeviceNet Error 84

I have a customer who is having a problem with his DeviceNet network with a 1769-SDN scanner. I was on site yesterday and they had a node number flashing on the scanner display followed by error code 84. The device was a RightSight sensor but my understanding from the troubleshooting guide is that error code 84 means the Scanner is initializing the DeviceNet Channel and the error code will clear itself once the scanner attempts to initialize all slave devices on the channel. This leads me to believe this error relates to the scanner rather than the device. The green LED of the sensor was flashing at the time and it's I-O status was not being updated in the plc and it had been like this for several days. We cycled the power yesterday and the fault cleared. The customer explained they have been experiencing this for a while on this line and has contacted me again today saying they have the same error now but on a different sensor.

I suspect the scanner might need replacing but wondered if anyone had come across anything similar?