I have not set the ValueMember property, but I get the Exception.

This is my desinger code

this.uc_Type.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right)));
this.uc_Type.CheckedListSettings.CheckStateMember = "Selected";
this.uc_Type.CheckedListSettings.EditorValueSource = Infragistics.Win.EditorWithComboValueSource.CheckedItems;
ugColumn_Selected.AutoSizeMode = Infragistics.Win.UltraWinGrid.ColumnAutoSizeMode.AllRowsInBand;
ugColumn_Selected.DataType = typeof(bool);
ugColumn_Selected.Header.Caption = "";
ugColumn_Selected.Header.CheckBoxVisibility = Infragistics.Win.UltraWinGrid.HeaderCheckBoxVisibility.Always;
ugColumn_Selected.Header.VisiblePosition = 0;
ugColumn_Selected.Width = 27;
ugc_Type.AutoSizeMode = Infragistics.Win.UltraWinGrid.ColumnAutoSizeMode.AllRowsInBand;
ugc_Type.Header.Caption = "Type";
ugc_Type.Header.VisiblePosition = 1;
ultraGridBand1.Columns.AddRange(new object[] {
ugColumn_Selected,
ugc_Type});
appearance14.TextHAlignAsString = "Center";
ultraGridBand1.Override.CellAppearance = appearance14;
appearance15.TextHAlignAsString = "Center";
ultraGridBand1.Override.HeaderAppearance = appearance15;
this.uc_Type.DisplayLayout.BandsSerializer.Add(ultraGridBand1);
this.uc_Type.DisplayStyle = Infragistics.Win.EmbeddableElementDisplayStyle.WindowsVista;
this.uc_Type.DropDownStyle = Infragistics.Win.UltraWinGrid.UltraComboStyle.DropDownList;
this.uc_Type.Location = new System.Drawing.Point(84, 73);
this.uc_Type.Name = "uc_Type";
this.uc_Type.PreferredDropDownSize = new System.Drawing.Size(0, 0);
this.uc_Type.Size = new System.Drawing.Size(175, 22);
this.uc_Type.TabIndex = 24;
this.uc_Type.AfterCloseUp += new System.EventHandler(this.uc_Type_AfterCloseUp);
this.uc_Type.BeforeDropDown += new System.ComponentModel.CancelEventHandler(this.uc_Type_BeforeDropDown);

Hi guidegi,

Looking at the code everything looks fine. I created a similar sample which is working just perfect. When the ValueMember is not set, the CheckStateMember can be set to any column, containing data type that can be converted to and from the boolean data type and there is no reason for throwing exception. I believe that something else in your application could be causing the exception, but I need a sample to be able to make a further investigation. If you could please send me a small sample catching the Exception, it will be much easier for me to help you. 

I removed the code that set CheckStateMember property from designer, and then add that code into Form creator.

In this case, the designer error does not occur any more.

In the case that UlraCombo has the UltraColumn of which key is "Selected", I can not set the CheckStateMember property to "Selected".

This is the reason why desingner error occured.

I am wondering why I can not set the CheckStateMember property in the desinger.

Is this a kind of bug?

Hi guidegi,

I wanted to know if you were able to solve your issue based on these suggestions or you still need help. Please let me know.