Enclosure Services Issue

Hi,everyone.

I have an old NetApp FAS6220 with 8.1.4P9D18 7-Mode.

Now a days, I can see many of CRITICAL log each hour.

[FAS6220-B:ses.access.sesUnavailable:CRITICAL]: Enclosure Services unavailable for one or more shelves on channel 1b.

However,There is no alarm on SystemManager and no alarm light on controller.

My service seems running normally too.

Since it's an old device the Maker warranty is out of date.

Could you please help sovle this issue.

Thx