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E42 — OTA_VERIFY_FAILED

The OTA firmware image failed verification after being written to flash.

What happens​

The error is logged and execution falls through — the WebSocket connection and normal operation continue. The OTA state may be left in an inconsistent state until the next reconnect cycle. The device will not reboot automatically.

Possible causes​

  • The firmware download was corrupted (checksum/signature mismatch). This can happen if the WebSocket connection dropped mid-transfer.
  • The firmware binary on the update server is itself corrupted.

How to fix​

  1. Retry the OTA update — Trigger the update again from the FKMTime web interface. A successful update will complete verification correctly.
  2. Check server-side firmware binary — Confirm the binary hosted for updates is not corrupted (re-upload if necessary).
  3. Contact support — Open an issue on GitHub if verification fails consistently.