When this message appears despite having the sensor plugged in and working previously, we have commonly seen that the machine has a previous dental software open (e.g. Eaglesoft, Vixwin, Dexis) at the same time as Dentiray Capture is being used.
The other software program that is open is taking ownership of the sensor and not allowing Dentiray Capture to "see" the device on the machine.
To remedy, close your previous capture software, and then open Dentiray Capture and attempt to capture an image.
Should this not resolve your issue, we recommend reaching out to your sensor's hardware manufacturer to assist.