System.InvalidOperationException: 'The binary operator NotEqual is not defined for the types
'Ant.Analysis.Infrastructure.Dtos.DataViews.QuestionsAnswerOptionsDataView' and
'Ant.Analysis.Infrastructure.Dtos.DataViews.QuestionsAnswerOptionsDataView'.'

public struct QuestionDetailDataView
{
    public Guid QuestionId { get; set; }
    public IQueryable<PreDefineAnswerOptionDataView> AnswerOptions { get; set; }
}

public struct PreDefineAnswerOptionDataView
{
    public Guid PreDefineAnswerOptionId { get; set; }
    public int DisplayOrder { get; set; }
    public string Text { get; set; }
}

var questionDetailDataView = (from question in Context.Questions.Where(question => question.ConsultationId == ConsultationId)
                  where question.IsSubQuestion == false
                  join questionHierarchy in Context.QuestionHierarchy on question.Id equals questionHierarchy.ParentQuestionId into qs
                  from childQuestion in qs.DefaultIfEmpty()
                  join subQuestion in questionListWithAnswerOptions on childQuestion.ChildQuestionId equals subQuestion.QuestionDetail.Id into questionSubQuestionAnswerOption
                  group questionSubQuestionAnswerOption by question into groupQuestionsAnswerOptions
     select new QuestionDetailDataView
        {
          QuestionId = groupQuestionsAnswerOptions.Key.Id,
          AnswerOptions = //Error is coming here, following script does work separately

                          (from preDefineAnswerOptionJoin in Context.QuestionPreDefineAnswerOptionJoin
                          where preDefineAnswerOptionJoin.QuestionId == groupQuestionsAnswerOptions.Key.Id
                          join preDefineAnswerOptions in Context.PreDefineAnswerOptions on preDefineAnswerOptionJoin.PreDefineAnswerOptionId equals preDefineAnswerOptions.Id
                           select new PreDefineAnswerOptionDataView
                              {
                                PreDefineAnswerOptionId = preDefineAnswerOptions.Id,
                                DisplayOrder = preDefineAnswerOptions.DisplayId,
                                Text = preDefineAnswerOptions.Text
                              })
                       }
                 ).ToList();