diff --git a/IRaCIS.Core.Application/Service/Management/DTO/UserFeedBackViewModel.cs b/IRaCIS.Core.Application/Service/Management/DTO/UserFeedBackViewModel.cs
index b3c1098b2..cb375a0db 100644
--- a/IRaCIS.Core.Application/Service/Management/DTO/UserFeedBackViewModel.cs
+++ b/IRaCIS.Core.Application/Service/Management/DTO/UserFeedBackViewModel.cs
@@ -91,7 +91,7 @@ namespace IRaCIS.Core.Application.ViewModel
         public List<string> ScreenshotList { get; set; }
 
         [JsonIgnore]
-        public string ScreenshotListStr { get; set; }
+        public string ScreenshotListStr { get; set; } = string.Empty;
     }