Fix #78734

src/vs/workbench/contrib/markers/browser/markersTreeViewer.ts

@@ -334,10 +334,12 @@ class MarkerWidget extends Disposable {
 			const sourceMatches = filterData && filterData.sourceMatches || [];
 			source.set(marker.source, sourceMatches);
 
+			if (marker.code) {
 				const code = new HighlightedLabel(dom.append(parent, dom.$('.marker-code')), false);
 				const codeMatches = filterData && filterData.codeMatches || [];
 				code.set(marker.code, codeMatches);
 			}
+		}
 
 		const lnCol = dom.append(parent, dom.$('span.marker-line'));
 		lnCol.textContent = Messages.MARKERS_PANEL_AT_LINE_COL_NUMBER(marker.startLineNumber, marker.startColumn);