Uncaught TypeError: Cannot read property 'isActive' of undefined (fixes #27257)

src/vs/workbench/browser/parts/editor/tabsTitleControl.ts

@@ -212,7 +212,7 @@ export class TabsTitleControl extends TitleControl {
 
 	private updateDropFeedback(element: HTMLElement, isDND: boolean, index?: number): void {
 		const isTab = (typeof index === 'number');
-		const isActiveTab = isTab && this.context.isActive(this.context.getEditor(index));
+		const isActiveTab = isTab && this.context && this.context.isActive(this.context.getEditor(index));
 
 		// Background
 		const noDNDBackgroundColor = isTab ? this.getColor(isActiveTab ? TAB_ACTIVE_BACKGROUND : TAB_INACTIVE_BACKGROUND) : null;