xpath expression evaluation does not work in 8.1.2

I have tried the following simple xml:



<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
             xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
    <persistence-unit name="MonitorServiceCache">

        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

        <properties>
            <property name="eclipselink.jdbc.driver" value="org.h2.Driver"/>
            <property name="eclipselink.jdbc.url" value="jdbc:h2:mem:monitorServiceDB"/>
            <!-- I work in this example without user / password.-->
            <property name="eclipselink.jdbc.user" value="monitorServiceCache"/>
            <property name="eclipselink.jdbc.password" value=""/>

            <!-- EclipseLink should create the database schema automatically -->

            <property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
            <property name="eclipselink.ddl-generation.output-mode" value="database"/>
            <property name="eclipselink.target-database" value="HSQL"/> <!--Is this necessary???-->
        </properties>

    </persistence-unit>
</persistence>