Problem Generating model with modx

 modx_VLE_Pupils
	Field           Type            Null    Default
	RoleNum	int(11)			No	None	auto_increment	 	 	 	 	 	 	
	FirstName	varchar(30)	No	None		 	 	 	 	 	 	 
	MiddleName	varchar(30)	Yes	NULL		 	 	 	 	 	 	 
	SurName	        varchar(30)	No	None		 	 	 	 	 	 	 
	DOB	        date		No	None		 	 	 	 	 	 	
	Gender	        varchar(1)	No	None		 	 	 	 	 	 	 
	YearGroup	int(11)		Yes	NULL		 	 	 	 	 	 	
	Group	        varchar(2)	Yes	NULL		 	 	 	 	 	 	 
	House	        varchar(6)	Yes	NULL		 	 	 	 	 	 	 
	Religion	        varchar(20)	Yes	NULL		 	 	 	 	 	 	 
	HomeLang	        varchar(20)	Yes	NULL		 	 	 	 	 	 	 
	Status	        varchar(8)	No	None		 	 	 	 	 	 	 

modx_VLE_Parents
	Field	        Type	        Null	Default
	ParentId	        int(11)		No	None	auto_increment	 	 	 	 	 	 	
	FirstName	varchar(30)	No	None		 	 	 	 	 	 	 
	SurName	        varchar(30)	No	None		 	 	 	 	 	 	 
	MobileNum	varchar(11)	Yes	NULL		 	 	 	 	 	 	 
	LandNum	        varchar(11)	Yes	NULL		 	 	 	 	 	 	 
	Address1	        varchar(30)	Yes	NULL		 	 	 	 	 	 	 
	Address2	        varchar(30)	Yes	NULL		 	 	 	 	 	 	 
	Address3	        varchar(30)	Yes	NULL		 	 	 	 	 	 	 
	PostCode	        varchar(8)	Yes	NULL		 	 	 	 	 	 	 
	Priority 	int(11)		No	None		 	 	 	 	 	 	

modx_VLE_Pupils-Parent
	Field	        Type		Null	Default	
	PupilRoleNum	int(11)		No	None		 	 	 	 	 	 	
	ParentRoleNum	int(11)		No	None		 	 	 	 	 	 	

vle.mysql.schema.xml
<?xml version="1.0" encoding="UTF-8"?>
<model package="VLE" baseClass="xPDOObject" platform="mysql" defaultEngine="MyISAM"
     phpdoc-package="VLE" phpdoc-subpackage="">

    <object class="VLEPupil" table="VLE_Pupils" extends="xPDOObject">
        <field key="RoleNum"    dbtype="int"     precision="11" phptype="integer" null="false" default="" index="index"/>
        <field key="FirstName"  dbtype="varchar" precision="30" phptype="string" null="false" default="" />
	<field key="MiddleName" dbtype="varchar" precision="30" phptype="string" null="true" default="" />
	<field key="SurName"    dbtype="varchar" precision="30" phptype="string" null="false" default="" />
	<field key="DOB"        dbtype="date"    precision=""  phptype="date" null="false" default="" />
	<field key="Gender"     dbtype="varchar" precision="1" phptype="string" null="false" default="" />
	<field key="YearGroup"  dbtype="int"     precision="11" phptype="integer" null="true" default="" />
	<field key="Group"      dbtype="varchar" precision="2"  phptype="string" null="true" default="" />
	<field key="House"      dbtype="varchar" precision="6"  phptype="string" null="true" default="" />
	<field key="Religion"   dbtype="varchar" precision="20" phptype="string" null="true" default="" />
	<field key="HomeLang"   dbtype="varchar" precision="20" phptype="string" null="true" default="" />
	<field key="Status"     dbtype="varchar" precision="8"  phptype="string" null="false" default="" />

         <composite alias="VLEPupilParent" class="VLEPupilParent" local="RoleNum" foreign="PupilRoleNum" cardinality="many" owner="local" />
    </object>

    <object class="VLEParent" table="VLE_Parents" extends="xPDOObject">
        <field key="ParentId"   dbtype="int"     precision="11" phptype="integer" null="false" default="" index="index"/>
        <field key="FirstName"  dbtype="varchar" precision="30" phptype="string" null="false" default="" />
        <field key="SurName"    dbtype="varchar" precision="30" phptype="string" null="false" default="" />
	<field key="MobileNum"  dbtype="varchar" precision="11" phptype="string" null="true" default="" />
	<field key="LandNum"    dbtype="varchar" precision="11" phptype="string" null="true" default="" />
	<field key="Address1"   dbtype="varchar" precision="30" phptype="string" null="true" default="" />
	<field key="Address2"   dbtype="varchar" precision="30" phptype="string" null="true" default="" />
	<field key="Address3"   dbtype="varchar" precision="30" phptype="string" null="true" default="" />
	<field key="PostCode"   dbtype="varchar" precision="8"  phptype="string" null="true" default="" />
	<field key="Priority"   dbtype="int"     precision="11" phptype="integer" null="false" default="" />

        <composite alias="VLEPupilParent" class="VLEPupilParent" local="ParentId" foreign="ParentRoleNum" cardinality="many" owner="local" />
    </object>

    <object class="VLEPupilParent" table="VLE_Pupils-Parent" extends="xPDOObject">
        <field key="PupilRoleNum"   dbtype="int" precision="11" phptype="integer" null="false" default="" />
        <field key="ParentRoleNum"  dbtype="int" precision="11" phptype="integer" null="false" default="" />

        <aggregate alias="Pupil" class="VLEPupil" local="PupilRoleNum" foreign="RoleNum" cardinality="one" owner="foreign" />
        <aggregate alias="Parent" class="VLEParent" local="ParentRoleNum" foreign="ParentId" cardinality="one" owner="foreign" />
    </object>
</model>

build.VLE.php

<?php
// sets up the MODX_ defines and the paths to the xPDO core
// you'll want to change this first line to point to the actual MODx install path
define('MODX_BASE_PATH', dirname(dirname(dirname(dirname(dirname(dirname(__FILE__)))))) . '/development/');
define('MODX_CORE_PATH', MODX_BASE_PATH.'core/');
require_once (MODX_CORE_PATH . 'config/config.inc.php');
include_once (MODX_CORE_PATH . 'model/modx/modx.class.php');

// first get the actual trunk path
$trunk = dirname(dirname(dirname(__FILE__)));

// create the modx object and load the modPackageBuilder class
$modx = new modX();
$modx->loadClass('transport.modPackageBuilder','',false, true);
$builder = new modPackageBuilder($modx);

// build the schema, using the PackageBuilder's buildSchema function. It takes 2 parameters:
// - the location of the model directory where you want the files to generate to
// - the schema xml file

$builder->buildSchema($trunk.'/assets/model/',$trunk.'/_build/schema/vle.mysql.schema.xml');

echo 'Finished!';
exit();
?>

$modx->initialize('mgr');