Check the log and prompt the watchdog to reset.
log-msg ：restored watchdog attitude 1 -1 123.
What is the reason for the reset of the watchdog error code indication？
Check over at Aurdupilot forums, someone may get you to upload a stack dump for analysis, or something like that.
I would say at least update your firmware version to latest stable, as some watchdog/reset issues had been fixed a while ago.
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