The most common cause for a Schick Sensor not to register acquisition or to throw out errors when attempting to ready the sensor for acquisition is if another imaging software is open. Most imaging software including Dentiray Capture will require exclusive use of the Schick Sensor device drivers so if one program (such as Eaglesoft) is already open, it will have those device drivers locked and that will prevent other software from being able to utilize the sensor.
If there is another software open that is configured to use the Schick Sensor you will need to close both the other software and Dentiray Capture, and then re-launch Dentiray Capture to allow it to initialize those Schick Sensor device drivers.
In rarer cases, sometimes a reboot is required to free up the Schick Sensor drivers for use with Dentiray Capture in which case launching other softwares configured to use them would not be recommended going forward.