All the Model properties are binded as string and it throws "The value XX is not valid" in ModelState validation

Question

I am getting value XX is not valid. But I am binding the correct datatype to the Model and I am still getting this error. Please find the error in . My controller is considering all datatype besides string to be not valid. Even the StartData and EndDate is throwing the same exception though I am binding the correct datatype.

I am not sure am I missing anything here. The worse part here is if I try to implement same (file) in another sample project it is working fine.

Following is my Model

public class Dept_User_Link
    {
        public Dept_User_Link()
        {
            StartDate = DateTime.Now;
            EndDate = DateTime.Now;
        }

        private List<Dept_User_Link> deptUserLink = new List<Dept_User_Link>();
        public int ID { get; set; }
        [Required]
        public int DeptID { get; set; }
        [Required]
        public int UserID { get; set; }
        [Required]
        public Guid Dummy { get; set; }
        [Required]
        public DateTime StartDate { get; set; }
        [Required]
        [DateRange(StartDateEditFieldName = "StartDate")]
        public DateTime EndDate { get; set; }

}

and following is my controller

      public ActionResult GridVwPartial()
            {
                var model = new Dept_User_Link().GetDeptUsersLink();
                ViewData["Departments"] = new Department().GetDepartments().Select(x => new { DeptID = x.ID, Name = x.Name }).ToList();
                ViewData["Users"] = new Users().GetUsers().Select(x => new { UserID = x.ID, Name = x.Name }).ToList();
                ViewData["GuidVals"] = new GuidVal().GuidValData();
                return PartialView("GridVwPartial", model);
            }

  public ActionResult AddNew(Dept_User_Link data) {
            // Add 'data' values to the underlying datasource
            // ...

            var model = new Dept_User_Link().GetDeptUsersLink();
            ViewData["Departments"] = new Department().GetDepartments().Select(x => new { DeptID = x.ID, Name = x.Name }).ToList();
            ViewData["Users"] = new Users().GetUsers().Select(x => new { UserID = x.ID, Name = x.Name }).ToList();

            return GridVwPartial();
        }

and following is my View

@using ROCKtree.CCTVWeb.Models
@model IList<Dept_User_Link>
@{


    Html.DevExpress().GridView<Dept_User_Link>(settings =>
    {
        settings.Name = "cascadingExample";
        settings.CallbackRouteValues = new { Controller = "Grid", Action = "GridVwPartial" };
        settings.SettingsEditing.AddNewRowRouteValues = new { Controller = "Grid", Action = "AddNew" };
        settings.CommandColumn.Visible = true;
        settings.CommandColumn.ShowNewButtonInHeader = true;
        settings.SettingsEditing.Mode = GridViewEditingMode.EditForm;
        settings.KeyFieldName = "ID";

        settings.Columns.Add(m => m.DeptID, column =>
        {
            column.EditorProperties().ComboBox(x =>
            {
                x.TextField = "Name";
                x.ValueField = "DeptID";
                x.DataSource = ViewData["Departments"];
                x.ClientSideEvents.SelectedIndexChanged = "OnSelectedDeptChanges";
                x.ValidationSettings.CausesValidation = true;
                //x.ClientSideEvents.SelectedIndexChanged = "";
            });
        });

        settings.Columns.Add(m => m.UserID, column =>
        {
            column.EditorProperties().ComboBox(x =>
            {
                x.TextField = "Name";
                x.ValueField = "UserID";
                //x.DataSource = ViewData["Users"];
                x.LoadDropDownOnDemand = true;
                x.CallbackRouteValues = new { Controller = "Grid", Action = "UserCallback" };
                x.ClientSideEvents.BeginCallback = "UserComboBox_BeginCallback";
                // x.ClientSideEvents.SelectedIndexChanged = "";

            });

        });

        settings.Columns.Add(m => m.Dummy, column =>
        {
            column.EditorProperties().ComboBox(cmb =>
            {
                cmb.TextField = "Name";
                cmb.ValueField = "ID";
                cmb.DataSource = ViewData["GuidVals"];
            });
        });


        settings.Columns.Add(m => m.StartDate, column =>
        {
            column.EditorProperties().DateEdit(clm =>
            {
                clm.TimeSectionProperties.Visible = true;
                clm.DisplayFormatString = "dd-MMM-yy HH:mm";
                clm.DisplayFormatInEditMode = true;
                clm.TimeSectionProperties.TimeEditProperties.EditFormatString = "HH";
                clm.TimeSectionProperties.TimeEditProperties.EditFormat = EditFormat.Custom;
                clm.UseMaskBehavior = true;
                clm.ValidationSettings.ErrorDisplayMode = ErrorDisplayMode.ImageWithTooltip;
                clm.ValidationSettings.Display = Display.Dynamic;
                clm.ValidationSettings.CausesValidation = true;
                clm.ValidationSettings.SetFocusOnError = true;
            });
            //column.SetEditItemTemplateContent(c =>
            //{
            //    ViewContext.Writer.Write("<div class='form-group'><div class='input-group date' id='datetimepicker1'><input type='text' class=\"form-control\" /><span class=\"input-group-addon\">");
            //    ViewContext.Writer.Write("<span class=\"glyphicon glyphicon-calendar\"></span></span></div></div>");
            //});
        });


        settings.Columns.Add(m => m.EndDate, column =>
        {
            column.EditorProperties().DateEdit(clm =>
            {
                clm.TimeSectionProperties.Visible = true;
                clm.DisplayFormatString = "dd-MMM-yy HH:mm";
                clm.DisplayFormatInEditMode = true;
                clm.TimeSectionProperties.TimeEditProperties.EditFormatString = "HH";
                clm.TimeSectionProperties.TimeEditProperties.EditFormat = EditFormat.Custom;
                clm.UseMaskBehavior = true;
                clm.ValidationSettings.ErrorDisplayMode = ErrorDisplayMode.ImageWithTooltip;
                clm.ValidationSettings.Display = Display.Dynamic;
                clm.ValidationSettings.CausesValidation = true;
                clm.ValidationSettings.SetFocusOnError = true;
            });
            //column.SetEditItemTemplateContent(c =>
            //{
            //    ViewContext.Writer.Write("<div class='form-group'><div class='input-group date' id='datetimepicker1'><input type='text' class=\"form-control\" /><span class=\"input-group-addon\">");
            //    ViewContext.Writer.Write("<span class=\"glyphicon glyphicon-calendar\"></span></span></div></div>");
            //});
        });
    }).Bind(Model).GetHtml();
}

Data for the Dummy Property

   public IList<GuidVal> GuidValData()
            {
                if (guidVal == null || guidVal.Count() == 0)
                {
                    //List<Department> deptList = new List<Department>();
                    List<string> deptValues = File.ReadLines(path).ToList();

                    foreach (string data in deptValues)
                    {
                        if (!string.IsNullOrEmpty(data))
                        {
                            string[] str = data.Split(separators, StringSplitOptions.None);
                            GuidVal deptLnk = new GuidVal();
                            deptLnk.ID = Guid.Parse(str[0]);
                            deptLnk.Name = str[1];
                            this.guidVal.Add(deptLnk);
                        }
                    }
                }
                return guidVal;

            }