All-In-One or scanner is not communicating with the computer
Make sure:
The All-In-One is plugged into a power source and the Power light is on.
The correct All-In-One is selected in the Device pop-up menu located in the Lexmark All-In-One Center Main Page.
Note:
The Device pop-up menu displays only when there is more than one Lexmark All-In-One software installed on your computer.
The All-In-One is securely connected to your computer through a USB cable or a USB hub.
There is enough power to run your All-In-One. Some USB bus powered hubs may not supply enough power. Plug the All-In-One directly into the computer's USB port and try again.