Fix 23421 (#23802)

frontend/src/metabase/query_builder/components/DatasetEditor/DatasetEditor.jsx

@@ -261,7 +261,7 @@ function DatasetEditor(props) {
 
   const focusFirstField = useCallback(() => {
     const [firstField] = fields;
-    setFocusedFieldRef(firstField.field_ref);
+    setFocusedFieldRef(firstField?.field_ref);
   }, [fields, setFocusedFieldRef]);
 
   useEffect(() => {

frontend/test/metabase/scenarios/models/reproductions/23421-visualization-settins-breaks-ui.cy.spec.js

@@ -15,7 +15,7 @@ const questionDetails = {
   dataset: true,
 };
 
-describe.skip("issue 23421", () => {
+describe("issue 23421", () => {
   beforeEach(() => {
     restore();
     cy.signInAsAdmin();