Improve TableConfig validation

netbox/extras/models/models.py

@@ -613,6 +613,31 @@ class TableConfig(CloningMixin, ChangeLoggedModel):
             items.append((col, ascending))
         return items
 
+    def clean(self):
+        super().clean()
+
+        # Validate table
+        if self.table_class is None:
+            raise ValidationError({
+                'table': _("Unknown table: {name}").format(name=self.table)
+            })
+
+        table = self.table_class([])
+
+        # Validate ordering columns
+        for name in self.ordering:
+            if name not in table.columns:
+                raise ValidationError({
+                    'ordering': _('Unknown column: {name}').format(name=name)
+                })
+
+        # Validate selected columns
+        for name in self.columns:
+            if name not in table.columns:
+                raise ValidationError({
+                    'columns': _('Unknown column: {name}').format(name=name)
+                })
+
 
 class ImageAttachment(ChangeLoggedModel):
     """

netbox/templates/extras/tableconfig_edit.html

@@ -3,8 +3,6 @@
 {% load i18n %}
 
 {% block form %}
-    {% render_errors form %}
-
   <div class="field-group my-5">
     <div class="row">
       <h2 class="col-9 offset-3">{% trans "Device" %}</h2>
@@ -47,5 +45,4 @@
       </div>
     </div>
   </div>
-
 {% endblock %}

netbox/utilities/tables.py

@@ -13,7 +13,10 @@ __all__ = (
 
 def get_table_for_model(model, name=None):
     name = name or f'{model.__name__}Table'
+    try:
         return import_string(f'{model._meta.app_label}.tables.{name}')
+    except ImportError:
+        return
 
 
 def get_table_ordering(request, table):