Fatal error: Uncaught Error: Call to a member function obtener_listado_venta_columna() on null in /var/www/html/modulo_venta_anticipada.php:2 Stack trace: #0 /var/www/html/eventos2.php(123): include() #1 /var/www/html/modulos/engine/engine.php(543): include_once('/var/www/html/e...') #2 /var/www/html/index.php(14): include_once('/var/www/html/m...') #3 {main} thrown in /var/www/html/modulo_venta_anticipada.php on line 2