While scanning there are times when a cable becomes loose. Use only USB 3.0 ports and if using a USB hub it should be powered.
Verify cables and USB connections and try again.
If it continues please reboot your computer and restart the SOL software.
Sometimes, it has been a problem with the CH340 driver. The file from the link below should help with it.
Open the application, click "Uninstall" to remove the existing drivers, then click "install" which will update the CH340 driver set. Checking 'Device Manager', 'Ports' again should now report USB-SERIAL CH340
Also verify the hardware meets our requirements. Additional technical information might be found here: FAST FACTS
Still experiencing issues? Please don't hesitate to contact our support here.