Whenever the famous red led appears (Left for Scanner | Right for Tablet), it means that Passportscan wasn't able to recognize the tablet by any reason. Here you can find a few common problems:
1 - Restart Wacom's service.
2 - It might also happen that PassportScan is not able to detect the tablet because it was switched off. If you first open PassportScan and then you switch on the tablet, you will need to restart Passportscan since it is not able to get the control of the scanner driver. We only call the driver when you first open the program, if the tablet was not powered before opening Passportscan you will need to restart the software.
3 - We always try to configure our client's system with a full performance power plan. But Windows has default option that will let your USB port in standby whenever you don't use it for a long time period. If this happens, we will help you out to solve the problem. But in order to make it work right now, you might want to unplug your tablet USB cable and connect it to a different port. Restart the app and that should solve the problem, as well as restarting the whole computer.
If these few tricks are not working for you, we might have to reinstall the drivers, send us a ticket and we will investigate the problem for you.