Fatal error: Uncaught Error: Cannot use assign-op operators with string offsets in /var/www/sigicov_sign/shared/graficos/pChart/pChart.class:2004 Stack trace: #0 /var/www/sigicov_sign/shared/graficos/Example23.php(36): pChart->drawStackedBarGraph() #1 {main} thrown in /var/www/sigicov_sign/shared/graficos/pChart/pChart.class on line 2004