linq group by id和sum of sum of null（undefined）

Question

var approverlist = _db.ApprvRejClaimTravelCashByApproverIdIPhone(ProjectSession.CompanyUserId, ProjectSession.CompanyId, Status).AsEnumerable().ToList();`
var results =
    from item in approverlist
    group item by item.ClaimId
        into g
        select new
        {
            ClaimId = g.Key,
            Name = g.First().Name,
            Amount = g.Sum(s => s.Amount),
            Description = g.First().Description,
            Status = g.First().Status,
            CreatedDate = g.First().CreatedDate,
            SubmitedDate = g.First().SubmitedDate,
            FullName = g.First().FullName,
            ApproverStatus = g.First().ApproverStatus,
            CurrencySymbol = g.First().CurrencySymbol,
            chkbox = g.First().chkbox,
            IsHierarchy = g.First().IsHierarchy,
            ColumnCategory = g.First().ColumnCategory,
            ColumnCategoryCode = g.First().ColumnCategoryCode
        };

return Json(results.ToDataSourceResult(request));

当我将此结果绑定到我的kendo mvc网格时，

在列数量中未定义，任何人都知道为什么会发生这种情况？

也尝试下面一个但相同的结果未定义：

var results = from x in approverlist
              group x.ClaimId by new { x.ClaimId, x.Name, x.Description, x.Status, x.CreatedDate, x.SubmitedDate, x.FullName, x.ApproverStatus, x.CurrencySymbol, x.chkbox, x.IsHierarchy, x.ColumnCategory, x.ColumnCategoryCode }
              into g
              select new { g.Key.ClaimId, g.Key.Name, Amount = g.Sum(), g.Key.Description, g.Key.Status, g.Key.CreatedDate, g.Key.SubmitedDate, g.Key.FullName, g.Key.ApproverStatus, g.Key.CurrencySymbol, g.Key.chkbox, g.Key.IsHierarchy, g.Key.ColumnCategory, g.Key.ColumnCategoryCode };