System core files were found in /var/db/system/cores. Please create a ticket at https://jira.ixsystems.com/ and remove these files.
In fact this only file in this directory is sshd.core
As I am using sshd for connections between 2 TrueNAS appliances, I am reluctant to deleting this file because I do not want to damage my working configuration. This appeared after upgrade from TrueNAS-12.0.U1.1 to TrueNAS-12.0.U, The alarm appears on both systems.