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cmd_key version 4
EOS 3.1 compatibility update.
EOS 3.1 remapped the the STOP EFFECT key.
Note: Once you update your cmd_key to v4 STOP EFFECT will not function as before in v3.0 or below.
There is no need to updated your cmd_key if you are not using EOS 3.1 or above.
All cmd_keys shipping after Oct 1, 2023 have been updated to V4 for EOS 3.1. If you are using EOS 3.0, you can downgrade your firmware here.
WIndows 7 or higher required for update software - No MAC Support for updater application.