Bug 210635 Incorrect preview of chart after reverse categories.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/withaxes/PlotWith2DAxes.java
IllegalArgumentException
	{
		final Series[] sea = ax.getRuntimeSeries( );
		final int iSeriesCount = sea.length;
		Series se;
		DataSet ds;
		Object oV1, oV2, oMin = null, oMax = null;
		PluginSettings ps = PluginSettings.instance( );
		IDataSetProcessor iDSP = null;
		
		boolean bAnyStacked = false;
		for ( int i = 0; i < iSeriesCount; i++ )
		{
			if ( sea[i].isStacked( ) )
			{
				if ( sea[i].canBeStacked( ) )
				{
					bAnyStacked = true;
					continue;
				}
				else
				{
					throw new IllegalArgumentException( MessageFormat.format( Messages.getResourceBundle( rtc.getULocale( ) )
							.getString( "exception.unstackable.is.stacked" ), 
							new Object[]{
								sea[i]
							} ) );
				}
			}
			iDSP = ps.getDataSetProcessor( sea[i].getClass( ) );