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Firmware Version 1.0.1 incorporates the following fix:
In some cases, the flash may not fire correctly under specific shooting conditions.
EOS series models released in 2014 or later can be used for the firmware update*
*Excluding cameras below:
Firmware Version 1.0.1 is for flashes with firmware Version 1.0.0. If the flash's firmware is already Version 1.0.1, it is not necessary to update the firmware.
When updating the firmware of the flash, please review the instructions thoroughly before you download the firmware.
Preparations for a firmware update:
Before starting the firmware update operations, please confirm the contents of the download, and carefully read thoroughly the firmware update procedures.
Should you have any questions about the announcement, please contact the Authorized Service Facility in your area or you may contact the Call Center within your region.