Fatal error: Uncaught Error: Class 'Mantum_Model' not found in C:\MANTUM\xampp2\htdocs\MNT\ventasvariables\aplicaciones\modulos\gestiondocumental\modelo\_clases\Retencion.php:7
Stack trace:
#0 {main}
  thrown in C:\MANTUM\xampp2\htdocs\MNT\ventasvariables\aplicaciones\modulos\gestiondocumental\modelo\_clases\Retencion.php on line 7