To reproduce: - Set the column like this: GridViewMaskBoxColumn col = new GridViewMaskBoxColumn(); col.Mask = "&&&&&&&&&&"; col.MaskType = MaskType.Standard; col.FieldName = "Name"; col.TextMaskFormat = MaskFormat.IncludeLiterals; - Type two words and press enter. Workaround: public class MyRadMaskedEditBoxEditor : RadMaskedEditBoxEditor { public override object Value { get { if (this.MaskTextBox.Mask == "my mask") { return this.MaskTextBox.Value; } return base.Value; } set { base.Value = value; } } }