XML节点读取失败

XML代码为
XML code:
<manifest xmlns="http://www.imsglobal.org/xsd/imscp_v1p1" xmlns:imsmd="http://ltsc.ieee.org/xsd/LOM" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:adlcp="http://www.adlnet.org/xsd/adlcp_v1p3" xmlns:imsss="http://www.imsglobal.org/xsd/imsss" xmlns:adlseq="http://www.adlnet.org/xsd/adlseq_v1p3" xmlns:adlnav="http://www.adlnet.org/xsd/adlnav_v1p3" identifier="MANIFEST-E8FCA34EE7AD38F59300B53187B4A304" xsi:schemaLocation="http://www.imsglobal.org/xsd/imscp_v1p1 imscp_v1p1.xsd http://ltsc.ieee.org/xsd/LOM lom.xsd http://www.adlnet.org/xsd/adlcp_v1p3 adlcp_v1p3.xsd http://www.imsglobal.org/xsd/imsss imsss_v1p0.xsd http://www.adlnet.org/xsd/adlseq_v1p3 adlseq_v1p3.xsd http://www.adlnet.org/xsd/adlnav_v1p3 adlnav_v1p3.xsd">
<organizations default="ORG-321D1F4875621CF2CB3AD6DC6E4E0FC6">
<organization identifier="ORG-321D1F4875621CF2CB3AD6DC6E4E0FC6" structure="hierarchical">
<title>CDMA Planning</title>
<item identifier="ITEM-6560A6CC4FF92D84477A410E99C5B789" isvisible="true" identifierref="RES-2CE5491B7E34134668F620631346931B">
<title>Description1</title>
</item>
</organization>