If one does a forum search via the magnifying glass icon, they’ll find that others have had the error code 1100 when using Safepoint. One possible cause, files being copied to the My Cloud while a Safepoint is running a backup, to this error (and a possible solution) is mentioned in the first of the thread links below.
https://community.wd.com/t/safepoint-create-error-1100/148842
https://community.wd.com/t/safepoint-and-other-event-codes/95528/4
https://community.wd.com/t/event-code-1100/94976
https://community.wd.com/t/what-is-safepoint-error-event-code-1100/91848
https://community.wd.com/t/safepoint-error-1100-will-the-new-firmware-solve-the-issue/93192
