report blowing up

[Joe]

Seeing this error. I fall back to an earlier version of my report which doesn't do this, make  a few changes, and I see this again. Any help would be appreciated.

An error has occurred while rendering the report: System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Reporting.Processing.Table.ForEachCell(Action`1 action)
   at Telerik.Reporting.Processing.Table.MeasureContent(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.VisualElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.ProcessingElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.AbsolutePositionLayout.MeasureChildItems(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.AbsolutePositionLayout.MeasureContent(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.ReportSectionBase.MeasureContent(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.VisualElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.ProcessingElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.StackLayout.MeasureContent(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.Group.MeasureContent(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.VisualElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.ProcessingElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.StackLayout.MeasureContent(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.Report.MeasureContent(IMeasureContext context, SizeRF availableClientSize)
   at Telerik.Reporting.Processing.VisualElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.ProcessingElement.MeasureOverride(IMeasureContext context, SizeRF availableSize)
   at Telerik.Reporting.Processing.LayoutElement.MeasureElement(LayoutElement elementToMeasure, IMeasureContext context)
   at Telerik.Reporting.XamlRendering.SilverlightReportInteractive.MeasureReportCore(Report report, IMeasureContext measureContext)
   at Telerik.Reporting.BaseRendering.RenderingExtensionBase.Render(Report report, Hashtable renderingContext, Hashtable deviceInfo, CreateStream createStreamCallback, EvaluateHeaderFooterExpressions evalHeaderFooterCallback)

[Hadib Ahmabi]

See if you by any chance have a Table/Crosstab that does not have item in a certain cell (empty cell) or have elements with width/height = 0. 

[Joe]

Is there any way to determine what cell is causing the problem? Unfortunately the crosstab is fairly complicated.

[Hadib Ahmabi]

First check the designer.cs for 0 value sizes.

I don't believe there is an easy way to check for missing cells.
You can serialize the report to XML. In the XML, it might be easier to see what's missing (and you can also share it).

This problem,however, should occur only when you are messing with the crosstab programmatically. You need to check that there is an item assigned for each of the cells (Row * Col) + for the headers of the groups, etc.. 

My advice - if you are not building the crosstab dynamically, start over again and use the designer only.
If you are building it dynamically - create a sample one with the designer and then compare it to yours and see what you might be missing. 

[Steven]

You could create your own table cell iterator and apply a generic action on the cells within the table ItemDataBound event.

This way you can catch the error and easily get the Row and Column indexes.

I've received this error with a missing cell's ReportItem and when the the ReportItem was assigned directly to a Table.  
The fix for the second issue was to wrap the nested table into a Panel.

public static void ForEachCell(this Telerik.Reporting.Processing.Table table, Action<ITableCell> action)
{
    int count = table.Rows.Count;
    int num = table.Columns.Count;
    for (int i = 0; i < count; i++)
    {
        ITableCell tableCell = null;
        for (int j = 0; j < num; j = j + tableCell.ColumnSpan)
        {
            tableCell = table.GetCell(i, j);
            if (tableCell.RowIndex == i)
            {
                action(tableCell);
            }
        }
    }
}