In my test, the Select function will return error if the row is not in the displayed view. My workaround is to use the GetRowByKeyValue function to check if the newly added row is in the displayed view. If the row is not displayed this function will return null.

Based on your description, I think the scroll into focus script that cause the postback to get more data. Do you mind sharing the code snippet so we could do further testing?

In my test, the Select function will return error if the row is not in the displayed view. My workaround is to use the GetRowByKeyValue function to check if the newly added row is in the displayed view. If the row is not displayed this function will return null.

Based on your description, I think the scroll into focus script that cause the postback to get more data. Do you mind sharing the code snippet so we could do further testing?

Sure.

I tried both the New Row's Select() Method and the New Row's 1st editable cell's ActivateEdit() method. It focuses the field and if there is more data available, a postback occurs from the grid.

function AddNewInuring()
    {
        try 
        {
            // Get grid
            var grdInurings = ISGetObject("<%=this.grdInurings.ClientID%>");
            if (grdInurings == null) { return false; }
            
            // Create new row
            var newRow = grdInurings.RootTable.NewRow();
            if (newRow == null) { return false; }
            
            // Default new row's data
            // NOTE: Scroll to row before new row to avoid lag from WebGrid loading more data (if exist)
            grdInurings.ClearSelection();            
            DefaultNewInuringRow(newRow);
            newRow.AddPendingChanges();  
                     
            // Focus
            var treatyName = newRow.GetCells().GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_TREATYNAME%>");
            if (treatyName != null) { treatyName.ActivateEdit(); }
            
            return true;
        }
        catch (ex) { ShowJSException(ex); }       
    }    
    
    function DefaultNewInuringRow(row)
    {
        try
        {                
            if (row == null) { return; }
                                   
            // Selected
            var cells = row.GetCells();
            if (cells == null) { return; }                       
            var selected = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_ISSELECTED%>");
            if (selected != null) { selected.SetValue(false, true); }   
            
            // Treaty Name             
            var treatyName = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_TREATYNAME%>");
            if (treatyName != null) { WebGrid_SetFieldText(treatyName, ""); }
            
            // Portfolio Name List            
            UpdatePortfolioData(row, null);
            
            // Cedant Name
            var cedantName = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_CEDANTNAME%>");
            if (cedantName != null) { WebGrid_SetFieldText(cedantName, ""); }
            
            // Inuring Structure
            var inuringStructure = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_INURINGTYPE_ID%>");
            if (inuringStructure != null) 
            { 
                WebGrid_SetDropDownListValue(inuringStructure, "<%=Endurance.Re.Common.Data.CommonConstants.DROPDOWN_VALUE_SELECT%>", "<%=Endurance.Re.Common.Data.CommonConstants.DROPDOWN_ID_SELECT%>"); 
            }
            
            // Currency Code
            var currencyCode = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_CURRENCYCODE%>");
            if (currencyCode != null) { WebGrid_SetFieldText(currencyCode, "<%=Endurance.Re.AWB.Utility.AWBConstants.INURING_CURRENCYCODE_DEFAULT_VALUE%>"); }
            
            // Occurrency Limit            
            var occurrenceLimit = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_OCCURRENCELIMIT%>");
            if (occurrenceLimit != null) { WebGrid_SetFieldText(occurrenceLimit, "0"); }
            
            // Attachment
            var attachment = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_ATTACHMENT%>");
            if (attachment != null) { WebGrid_SetFieldText(attachment, "0"); }
            
            // Risk Limit
            var riskLimit = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_RISKLIMIT%>");
            if (riskLimit != null) { WebGrid_SetFieldText(riskLimit, "0"); }
             
            // Retention
            var retention = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_RETENTION%>");
            if (retention != null) { WebGrid_SetFieldText(retention, "0"); }
            
            // Placed
            var placed = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_PLACED%>");
            if (placed != null) { WebGrid_SetFieldText(placed, "0"); }
            
            // Covered
            var covered = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_COVERED%>");
            if (covered != null) { WebGrid_SetFieldText(covered, "0"); }
            
            // Effective Date
            var effectiveDate = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_EFFECTIVEDATE%>");
            if (effectiveDate != null) { WebGrid_SetFieldText(effectiveDate, ""); }
            
            // Expiration Date
            var expirationDate = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_EXPIRATIONDATE%>");
            if (expirationDate != null) { WebGrid_SetFieldText(expirationDate, ""); }
            
            // Premium
            var premium = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_PREMIUM%>");
            if (premium != null) { WebGrid_SetFieldText(premium, "0"); }
            
            // Coverage Basis
            var coverageBasis = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_COVERAGEBASISTYPE_ID%>");
            if (coverageBasis != null) 
            { 
                WebGrid_SetDropDownListValue(coverageBasis, "<%=Endurance.Re.Common.Data.CommonConstants.DROPDOWN_VALUE_SELECT%>", "<%=Endurance.Re.Common.Data.CommonConstants.DROPDOWN_ID_SELECT%>"); 
            }
            
            // Attachment Basis
            var attachmentBasis = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_ATTACHMENTBASISTYPE_ID%>");
            if (attachmentBasis != null) 
            { 
                WebGrid_SetDropDownListValue(attachmentBasis, "<%=Endurance.Re.Common.Data.CommonConstants.DROPDOWN_VALUE_SELECT%>", "<%=Endurance.Re.Common.Data.CommonConstants.DROPDOWN_ID_SELECT%>"); 
            }
            
            // Priority
            var priority = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_PRIORITY%>");
            if (priority != null) { WebGrid_SetFieldText(priority, "1"); }
            
            // Number of Reinstatements
            var numReinstatements = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_NUMREINSTATEMENTS%>");
            if (numReinstatements != null) { WebGrid_SetFieldText(numReinstatements, "1"); }
            
            // Reinstatement Charge
            var reinstatementCharge = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_REINSTATEMENTCHARGE%>");
            if (reinstatementCharge != null) { WebGrid_SetFieldText(reinstatementCharge, "0"); }
            
            // Source
            var source = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_SOURCE%>");
            if (source != null) { WebGrid_SetFieldText(source, "<%=Endurance.Re.AWB.Utility.AWBConstants.INURING_SOURCE_USER_DEFAULT_TEXT%>"); } 
            
            // Inuring Notes
            var inuringNotes = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_INURINGNOTES%>");
            if (inuringNotes != null) { WebGrid_SetFieldText(inuringNotes, ""); }
            
            // ID
            // NOTE: This is done to avoid any validation on the DataKeyField being unique
            var id = cells.GetNamedItem("<%=Endurance.Re.AWB.Utility.AWBConstants.SP_COL_INURING_GET_ID%>");
            if (id != null) 
            {
                var now = new Date();
	            WebGrid_SetFieldText(id, (now.getSeconds() + now.getMilliseconds()));
            }
        }
        catch (ex) { ShowJSException(ex); }              
    }        

<CommonCtrl:EnduranceWebGrid runat="server" ID="grdInurings" DefaultStyleMode="Elegant"
                                    UseDefaultStyle="True" Width="100%" Height="100%" ViewStateItems="All" OnInitializeDataSource="grdInurings_OnInitializeDataSource"
                                    OnInitializePostBack="grdInurings_OnInitializePostBack" OnPrepareDataBinding="grdInurings_OnPrepareDataBinding"
                                    OnInitializeLayout="grdInurings_OnInitializeLayout" OnInitializeRow="grdInurings_OnInitializeRow"
                                    OnUpdateRow="grdInurings_OnUpdateRow" OnExport="grdInurings_OnExport">
                                    <LayoutSettings AutoHeight="false" AutoWidth="false" AllowBatchUpdate="true" BatchUpdateSettings-PromptUnsavedChanges="false"
                                        BatchUpdateSettings-AutomaticObjectUpdate="false" AllowEdit="Yes" EditOnClick="True"
                                        AllowAddNew="Yes" AllowDelete="Yes" PromptBeforeDelete="true" NewRowLostFocusAction="AlwaysPrompt"
                                        ResetNewRowValuesOnError="True" RowHeightDefault="22px" AllowFilter="Yes" AllowSelectColumns="Yes"
                                        AllowSorting="Yes" HideColumnsWhenGrouped="Default" AllowExport="Yes" InProgressUIBehavior="ChangeCursorToHourGlass"
                                        ApplyFiltersKey="Enter" AllowColumnFreezing="Yes" ShowFilterStatus="True" PagingMode="VirtualLoad"
                                        VerboseEditingInformation="False" FilterBarVisible="True" PagingExportMode="ExportAllData"
                                        CellPaddingDefault="0" AlwaysShowHelpButton="False" VirtualPageSize="200">
                                        <ClientSideEvents OnInitialize="grdInurings_OnInitialize" OnRowContextMenu="grdInurings_OnRowContextMenu"
                                            OnRowValidate="grdInurings_OnRowValidate" OnRowSelect="grdInurings_OnRowSelect" />
                                        <FrameStyle>
                                            <BorderSettings>
                                                <Top Style="none" />
                                                <Bottom Style="none" />
                                                <Left Color="#6593cf" Width="1" Style="solid" />
                                                <Right Color="#6593cf" Width="1" Style="solid" />
                                            </BorderSettings>
                                        </FrameStyle>
                                        <HeaderStyle CssClass="WebGridHeaderStyle" />
                                        <StatusBarStyle CssClass="WebGridStatusBarStyle" />
                                        <StatusBarCommandStyle Active-CssClass="WebGridStatusBarCommandStyleActive" Normal-CssClass="WebGridStatusBarCommandStyleNormal"
                                            Over-CssClass="WebGridStatusBarCommandStyleOver">
                                            <Normal CssClass="WebGridStatusBarCommandStyleNormal">
                                            </Normal>
                                            <Over CssClass="WebGridStatusBarCommandStyleOver">
                                            </Over>
                                            <Active CssClass="WebGridStatusBarCommandStyleActive">
                                            </Active>
                                        </StatusBarCommandStyle>
                                        <FilterRowStyle CssClass="WebGridFilterRowStyle" />
                                        <PreviewRowStyle CssClass="WebGridRowStyle" />
                                        <RowStyle CssClass="WebGridRowStyle" />
                                        <QuickFilterBarStyle CssClass="WebGridRowStyle" />
                                        <RowHeaderStyle CssClass="WebGridRowHeaderStyle" />
                                        <SelectedRowStyle CssClass="WebGridSelectedRowStyle" />
                                        <EditFocusCellStyle CssClass="WebGridRowStyle" />
                                        <FocusCellStyle CssClass="WebGridRowStyle" />
                                        <LostFocusRowStyle CssClass="WebGridRowStyle" />
                                        <NewRowStyle CssClass="WebGridRowStyle" />
                                        <SortedColumnStyle CssClass="WebGridSortedColumnStyle" />
                                        <AlternatingRowStyle CssClass="WebGridAlternatingRowStyle" />
                                        <EditTextboxStyle CssClass="WebGridEditTextboxStyle" />
                                        <FreezePaneSettings ActiveFrozenColumns="4" ShowInContextMenu="False" ShowSplitterLine="False"
                                            MaxFrozenColumns="4" SplitterLineColor="ActiveBorder" SplitterLineWidth="1" />
                                    </LayoutSettings>
                                    <RootTable Caption="Inurings" DataKeyField="ID" NewRowInfoText="Please click here to create a new Inuring">
                                        <Columns>
                                            <ISWebGrid:WebGridColumn Caption="ID" Name="ID" DataMember="ID" DataType="System.Integer"
                                                ColumnType="Text" EditType="NoEdit" NewRowEditType="NoEdit" FilterEditType="NoEdit"
                                                Width="0px" Visible="false">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="IsReadOnly" Name="IsReadOnly" DataMember="IsReadOnly"
                                                DataType="System.Boolean" ColumnType="Text" EditType="NoEdit" NewRowEditType="NoEdit"
                                                FilterEditType="NoEdit" Width="0px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Select" Name="IsSelected" DataMember="IsSelected"
                                                DataType="System.Boolean" ColumnType="CheckBox" EditType="Checkbox" NewRowEditType="Checkbox"
                                                FilterEditType="Checkbox" Width="40px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Treaty Name" Name="TreatyName" DataMember="TreatyName"
                                                DataType="System.String" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="150px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Portfolio Name" Name="PortfolioNameList" DataMember="PortfolioNameList"
                                                DataType="System.String" ColumnType="Text" EditType="NoEdit" NewRowEditType="NoEdit"
                                                FilterEditType="TextBox" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="PortfolioIDList" Name="PortfolioIDList" DataMember="PortfolioIDList"
                                                DataType="System.String" ColumnType="Text" EditType="NoEdit" NewRowEditType="NoEdit"
                                                FilterEditType="NoEdit" Width="0px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Cedant" Name="CedantName" DataMember="CedantName"
                                                DataType="System.String" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Inuring Structure" Name="InuringTypeID" DataMember="InuringTypeID"
                                                DataType="System.Integer" ColumnType="Custom" EditType="DropdownList" NewRowEditType="DropdownList"
                                                FilterEditType="DropdownList" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Currency" Name="CurrencyCode" DataMember="CurrencyCode"
                                                DataType="System.String" ColumnType="Custom" EditType="DropdownList" NewRowEditType="DropdownList"
                                                FilterEditType="DropdownList" Width="70px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Occurrence Limit" Name="OccurrenceLimit" DataMember="OccurrenceLimit"
                                                DataType="System.Integer" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Attachment" Name="Attachment" DataMember="Attachment"
                                                DataType="System.Integer" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Risk Limit" Name="RiskLimit" DataMember="RiskLimit"
                                                DataType="System.Integer" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Retention" Name="Retention" DataMember="Retention"
                                                DataType="System.Integer" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="%Placed" Name="Placed" DataMember="Placed" DataType="System.Decimal"
                                                ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox" FilterEditType="TextBox"
                                                Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="%Covered" Name="Covered" DataMember="Covered" DataType="System.Decimal"
                                                ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox" FilterEditType="TextBox"
                                                Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Effective Date" Name="EffectiveDate" DataMember="EffectiveDate"
                                                DataFormatString="dd-MMM-yyyy" DataType="System.String" ColumnType="Text" EditType="CalendarCombo"
                                                NewRowEditType="CalendarCombo" FilterEditType="CalendarCombo" Width="90px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Expiry Date" Name="ExpirationDate" DataMember="ExpirationDate"
                                                DataFormatString="dd-MMM-yyyy" DataType="System.String" ColumnType="Text" EditType="CalendarCombo"
                                                NewRowEditType="CalendarCombo" FilterEditType="CalendarCombo" Width="90px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Premium" Name="Premium" DataMember="Premium" DataType="System.Integer"
                                                ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox" FilterEditType="TextBox"
                                                Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Coverage Basis" Name="CoverageBasisTypeID" DataMember="CoverageBasisTypeID"
                                                DataType="System.Integer" ColumnType="Custom" EditType="DropdownList" NewRowEditType="DropdownList"
                                                FilterEditType="DropdownList" Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Attachment Basis" Name="AttachmentBasisTypeID"
                                                DataMember="AttachmentBasisTypeID" DataType="System.Integer" ColumnType="Custom"
                                                EditType="DropdownList" NewRowEditType="DropdownList" FilterEditType="DropdownList"
                                                Width="100px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Priority" Name="Priority" DataMember="Priority"
                                                DataType="System.DateTime" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="50px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Number of Reinstatements" Name="NumReinstatements"
                                                DataMember="NumReinstatements" DataType="System.DateTime" ColumnType="Text" EditType="TextBox"
                                                NewRowEditType="TextBox" FilterEditType="TextBox" Width="150px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Reinstatement Charge" Name="ReinstatementCharge"
                                                DataMember="ReinstatementCharge" DataType="System.DateTime" ColumnType="Text"
                                                EditType="TextBox" NewRowEditType="TextBox" FilterEditType="TextBox" Width="125px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Source" Name="Source" DataMember="Source" DataType="System.String"
                                                ColumnType="Text" EditType="NoEdit" NewRowEditType="NoEdit" FilterEditType="TextBox"
                                                Width="50px">
                                            </ISWebGrid:WebGridColumn>
                                            <ISWebGrid:WebGridColumn Caption="Notes" Name="InuringNotes" DataMember="InuringNotes"
                                                DataType="System.String" ColumnType="Text" EditType="TextBox" NewRowEditType="TextBox"
                                                FilterEditType="TextBox" Width="300px">
                                            </ISWebGrid:WebGridColumn>
                                        </Columns>
                                    </RootTable>
                                </CommonCtrl:EnduranceWebGrid>

Based on the snippet you provided, you are using BatchUpdate feature and VirtualLoad paging. Under such scenario, you could set the Grid property HaltLoadMore set to true in order to abort the load more process once. In your case, you will need to set the property before invoking the Select or ActivateEdit method. Here is the snippet:

function AddRow()
{
    var grid = ISGetObject("WebGrid1");
    var newRow = grid.RootTable.NewRow(); // create new row object
    var cells = newRow.GetCells(); // get WebGridCell collection

    // populate new row object     
    .
    .
    .
    
    // insert new record
    newRow.AddPendingChanges();

    grid.HaltLoadMore = true
    newRow.GetCell(0).ActivateEdit();
    
}

Based on the snippet you provided, you are using BatchUpdate feature and VirtualLoad paging. Under such scenario, you could set the Grid property HaltLoadMore set to true in order to abort the load more process once. In your case, you will need to set the property before invoking the Select or ActivateEdit method. Here is the snippet:

function AddRow()
{
    var grid = ISGetObject("WebGrid1");
    var newRow = grid.RootTable.NewRow(); // create new row object
    var cells = newRow.GetCells(); // get WebGridCell collection

    // populate new row object     
    .
    .
    .
    
    // insert new record
    newRow.AddPendingChanges();

    grid.HaltLoadMore = true
    newRow.GetCell(0).ActivateEdit();
    
}