This is my first time using WebHierarchicalDataGrid.  I set up my webhierarchialgrid, but I am having issue.  I am getting the error below when trying to expand the child band. 

Error: Sys.ArgumentOutOfRangeException: Value must be an integer. Parameter name: x Actual value was NaN.

I don't understand why I am getting this error.  Please help!

Below is my code:

            <asp:Panel ID="Panel1" runat="server">
                <ig:WebHierarchicalDataGrid ID="whdgrd_project" runat="server" DataKeyFields="SEQNUM"
                    AutoGenerateColumns="False" AutoGenerateBands="false" DataSourceID="ds" >
                    <GroupingSettings>
                        <RemoveButton AltText="Ungroup Column" />
                    </GroupingSettings>
                    <Columns>
                       
                        <ig:TemplateDataField Key="CheckAll">
                        <HeaderTemplate>
                            <input id="chkAll" type="checkbox" onclick="CheckAllDataGridCheckBoxes('chkSelection',this.checked)">                       
                        </HeaderTemplate>
                        <ItemTemplate>
                            <asp:CheckBox ID="chkSelection" Runat="server"></asp:CheckBox>
                        </ItemTemplate>                       
                        </ig:TemplateDataField>

                        <ig:BoundDataField DataFieldName="SEQNUM" Key="SEQNUM" Header-Text="SEQNUM" />
                        <ig:BoundDataField DataFieldName="PLATFORM_NAME" Key="PLATFORM_NAME" Header-Text="Platform Name" />
                        <ig:BoundDataField DataFieldName="HULL_NAME" Key="HULL_NAME" Header-Text="Hull#" />
                        <ig:BoundDataField DataFieldName="CITY" Key="CITY" Header-Text="City" />
                        <ig:BoundDataField DataFieldName="STATE" Key="STATE" Header-Text="State" />
                        <ig:BoundDataField DataFieldName="EVENT_NAME" Key="EVENT_NAME" Header-Text="Event Name" />
                        <ig:BoundDataField DataFieldName="START_DATE" Key="START_DATE" Header-Text="Start Date" />
                        <ig:BoundDataField DataFieldName="END_DATE" Key="END_DATE" Header-Text="End Date" />

                        <ig:TemplateDataField Key="DeleteItem" Width="60px">
                            <ItemTemplate>
                                <asp:ImageButton runat="server" ID="DeleteItem" AlternateText="Delete"
                                    ImageUrl="../../USCG/images/btn_edit.jpg"/>
                            </ItemTemplate>
                        </ig:TemplateDataField>

                    </Columns>
                    <Bands>
                        <ig:Band DataMember="dv_assign" Key="Assign" AutoGenerateColumns="false"  DataKeyFields="PERSONNEL_SEQNUM" >
                            <Columns>
                                <ig:BoundDataField DataFieldName="PERSONNEL_SEQNUM" Key="PERSONNEL_SEQNUM" Header-Text="personnel seqnum" />
                                <ig:BoundDataField DataFieldName="LASTNAME" Key="LASTNAME" Header-Text="Last Name" />
                                <ig:BoundDataField DataFieldName="FIRSTNAME" Key="FIRSTNAME" Header-Text="First Name" />
                                <ig:BoundDataField DataFieldName="START_DATE" Key="START_DATE" Header-Text="Start Date" />
                                <ig:BoundDataField DataFieldName="END_DATE" Key="END_DATE" Header-Text="End Date" />
                                <ig:BoundDataField DataFieldName="PROJECT_SCHEDULER_SEQNUM" Key="PROJECT_SCHEDULER_SEQNUM" Header-Text="Project seqnum" />
                                <ig:BoundDataField DataFieldName="SEQNUM" Key="SEQNUM" Header-Text="SEQNUM" />

                            </Columns>
                        </ig:Band>
                    </Bands>
                   
                   
                    <CollapseButton AltText="Collapse Row" />
                    <ExpandButton AltText="Expand Row" />
                </ig:WebHierarchicalDataGrid>
                <ig:WebHierarchicalDataSource ID="ds" runat="server">
                <DataRelations>
                    <ig:DataRelation ChildDataViewID="dv_assign" ParentDataViewID="dv_event" ChildColumns="PROJECT_SCHEDULER_SEQNUM" ParentColumns="SEQNUM"  />
                </DataRelations>
                <DataViews>
                    <ig:DataView ID="dv_event" DataSourceID="events"/>
                    <ig:DataView ID="dv_assign" DataSourceID="assignedPersonnel"/>
                </DataViews>
                   
                </ig:WebHierarchicalDataSource>
                <asp:SqlDataSource ID="events" runat="server"
                    ConnectionString="Data Source=CIMS;User ID=CIMS;Password=s!_1128_1960;Unicode=True"
                    ProviderName="System.Data.OracleClient"
                    SelectCommand="SELECT * FROM &quot;USCG_V_PROJECT_TRACKER&quot;"></asp:SqlDataSource>
                <asp:SqlDataSource ID="assignedPersonnel" runat="server"
                    ConnectionString="Data Source=CIMS;User ID=CIMS;Password=s!_1128_1960;Unicode=True"
                    ProviderName="System.Data.OracleClient"
                    SelectCommand="SELECT &quot;LASTNAME&quot;, &quot;FIRSTNAME&quot;, &quot;START_DATE&quot;, &quot;END_DATE&quot;, &quot;PROJECT_SCHEDULER_SEQNUM&quot;, &quot;SEQNUM&quot; FROM &quot;USCG_V_PT_ASSIGNED&quot; ORDER BY &quot;LASTNAME&quot;"></asp:SqlDataSource>
            </asp:Panel>