Fehlerbehebung bei leerer DB;

MultipleChoiceTrainer/Models/HomeViewModel.cs

@@ -9,6 +9,6 @@ namespace MultipleChoiceTrainer.Models
     public class HomeViewModel
     {
         public IList<Category> Categories { get; set; }
-        public int SelectedCategoryId { get; set; }
+        public int? SelectedCategoryId { get; set; }
     }
 }