Led for HD 1 red & cautionary message in settings following update

When I checked myCloudmirror today, the led for HD1 was showing red and there was a caution message on accessing settings. I have run diagnostics and scanned eack disk which are set as a JBOD configuration. There are no reported errors and system is reported OK, temperature etc. fine.
I have just rebooted (lengthy) and the message now says healthy. Could you please advise if I should be concerned and suggest possible cause.

I note from the logs that there were a large number of FAILS of authentification e.g.
2016 Mar 30 10:09:11
CIFS: Authentication for user [myemail@blahblah] has FAILED.
I am that user and this log message was produced presumably before the lengthy reboot.
I have also recently had messages to the effect the WD was closing down. When checked the system appeared to be OK.
On coming onto the forum I note that this all seemed to coincide with an auto-update yesterday. Coincidence or something to worry about?
John B


Just to avoid any issues, keep an eye on your drive and make sure that you have your data backed up.

The Red light normally means that there’s an issue with the drive on that bay.