Yes, lolypop000 is right.
Flash the firmware using the ORIGINAL option of GarminCure3.
If the device does boot, but doesn't create the Garmin folder, then create it manually and reboot the device. Then check if the device creates Garmin/GarminDevice.xml.
If it does create Garmin/GarminDevice.xml, use WebUpdater.exe to restore the missing files.
Otherwise, we have a problem.