No cell validation UI shown?

[Dexter]

http://www.telerik.com/help/wpf/gridview-managing-data-validation.html

Hello, I would like to achieve the red validation pop-out message as shown in the 2nd picture from the link above. All my other codes are working, except for red pop-out message. Is there anything I'm overlooking? Below are my codes:

​

private void GridCommsEqp_OnCellValidating(object sender, GridViewCellValidatingEventArgs e)
        {
            switch (e.Cell.Column.UniqueName)
            {
                case "SSN":
                    if (e.NewValue.ToString().Length > 30)
                    {
                        e.IsValid = false;
                        e.ErrorMessage = string.Format("{0} must not be longer than 30 characters. " +
                                                       "Current length: {1}", e.Cell.Column.Header,
                                                       e.NewValue.ToString().Length);
                    }
                    break;
                case "OfficialDesc":
                case "CommonDesc":
        .
        .
        .
        }

[Yoan]

Hi Dexter,

I have prepared a sample project based on the provided code snippet and everything seems to work as expected. May I ask you to modify the attached project in order to reproduce the issue? Then you can send it back to me for further investigation.

Regards,
Yoan
Telerik