Hi Netgear,
Not necessarily. This could be recoverable too. If you are seeing such logs, it is most probably an issue the hardware. But it could be recoverable in some cases. I would suggest you reboot the FPC and check if the logs stop appearing. If not, you might have to consider permanent hardware damage. In case of permanent damage, you would be able to determine it on alarms, LEDs, FPC states as well. If alarm keeps repeating even after reboot, try using a different FPC in the same slot and you will have your answers. Make sure you are performing all steps considering that you will have impact to services running on the FPC every time it is rebooted or replaced.
HTH