Deleting the only zone in the UI reloaded the entry with no zones, and min() over an empty set of models raised during setup, so the entry failed to load. Counts and learning progress now default to 0, and the status reads "no_zones" until a zone is added again; adding one resumes normally. HA Core regression test included. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>