[Kani999]

Summary

Typed tabs save field names (field_infos) at ready(). When a Custom Object Type field is deleted or renamed after startup, those names no longer exist on the live dynamic model. The badge renders on every host detail page, so the stale names took down all of them:

 _badge(instance)
-  total = dynamic_model.objects.filter(q_filter).distinct().count()   # FieldError → 500
+  try: total = ...filter(q_filter).distinct().count()
+  except FieldError: log warning, return None                        # tab hidden
 _TypedTabView.get()
-  base_qs = dynamic_model.objects.filter(q_filter).distinct()        # FieldError → 500
+  try: base_qs = ...
+  except FieldError: base_qs = dynamic_model.objects.none()          # empty table

Evidence

• Before: every Device page →
  FieldError: Cannot resolve keyword 'device' into field. Choices are: bookmarks, contacts, created, id, ...
  at views/typed.py:239 in _badge. Hit in the netbox-authorized-keys test suite (fresh DB, no custom object fields).
  After: new test test_returns_none_when_field_no_longer_exists: filter() raises FieldError → badge returns None. pytest tests/ 37 passed, ruff clean.

Merge Danger

Door: two-way

No models or migrations. Rollback = pin 3.0.0.

Blast Radius: tabs

Affected types keep a hidden tab and an empty table until NetBox restarts, which re-reads the fields. A warning is logged each time.