diff --git a/IRaCIS.Core.Application/Service/Reading/ReadingImageTask/ReadingImageTaskService.cs b/IRaCIS.Core.Application/Service/Reading/ReadingImageTask/ReadingImageTaskService.cs
index e51b238a2..ebeb45bdb 100644
--- a/IRaCIS.Core.Application/Service/Reading/ReadingImageTask/ReadingImageTaskService.cs
+++ b/IRaCIS.Core.Application/Service/Reading/ReadingImageTask/ReadingImageTaskService.cs
@@ -2004,9 +2004,9 @@ namespace IRaCIS.Core.Application.Service
 
                 }).ToListAsync();
 
-                var markquestionId = inDto.QuestionMarkInfoList.Select(y => y.QuestionId).ToList();
+                var markquestionId = inDto.QuestionMarkInfoList.Select(y => (Guid?)y.QuestionId).ToList();
 
-                var needDeleteMarkQuestonIds = inDto.Answers.Where(x => x.Answer == string.Empty).Select(x => x.Id).ToList();
+                List<Guid?> needDeleteMarkQuestonIds = inDto.Answers.Where(x => x.Answer == string.Empty).Select(x => (Guid?)x.Id).ToList();
 
 
                 await _readingTaskQuestionMarkRepository.BatchUpdateNoTrackingAsync(x =>