Hi all. When I add my Loopback interface to isisd.conf and restart it, it throws the below: 2020/04/07 14:35:44 errors: ISIS: libyang: Missing required element "area-tag" in "isis". (/frr-interface:lib/interface[name='lo0'][vrf='default']/frr-isisd:isis) 2020/04/07 14:35:44 warnings: ISIS: [EC 100663337] nb_candidate_commit_prepare: failed to validate candidate configuration % Configuration failed: validation error. A bit of Googling indicated that "router isis 1" would need to come first in the configuration, since some previous versions of FRR processed the files line by line, and not atomically. But even after doing that, I still get the same error; but get this, ONLY when I add "interface lo0" to the configuration. Without that, and with just the physical interface in the configuration, IS-IS starts up fine. Any thoughts? System FRR 7.3 on FreeBSD-12.1. Thanks. Mark.