quick fix

app/Http/Controllers/ActivityController.php

@@ -165,7 +165,7 @@ class ActivityController extends Controller
 	}
 
 	public function getActivityLast($parentId){
-		$activity = Activity::where('parent_id', $parentId)->orderByRaw('actual_end DESC')->first(); 
+		$activity = Activity::where('parent_id', $parentId)->orderByRaw('actual_start DESC')->first(); 
 		if (!isset($activity)) {
 			return null;
 		}