Br as the only element raises an error

[pgundlach]

<?xml version="1.0" encoding="UTF-8"?>

<Layout xmlns="urn:speedata.de:2009/publisher/en" 
  xmlns:sd="urn:speedata:2009/publisher/functions/en"
  version="3.6.0">

  <Record element="data">
    <Output>
      <Text>
        <Paragraph>
          <Br/>
        </Paragraph>
      </Text>
    </Output>
  </Record>
</Layout>

This gives a black box but should be silently discarded.