You cannot perform the firmware update using CFast 2.0 cards. Please use a commercially available SD/SDHC/SDXC memory card that is 64MB or more for the firmware update.
Firmware Version 18.104.22.168 is for XC10 camcorders with Firmware Version 22.214.171.124 – 126.96.36.199. If your camcorder’s firmware is already Version 188.8.131.52, it is not necessary to update the firmware. Once the camcorder is updated to the latest version, it cannot be restored to a previous version.
For further information, please refer to the latest version of the unit’s Instruction Manual that is released with the firmware update.