[Pavel Antonov]

Должно быть так:

<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
<T3DataStructure>
    <meta type="array">
        <langDisable>1</langDisable>
    </meta>
    <ROOT type="array">
        <tx_templavoila type="array">
            <title>ROOT</title>
            <description>Select the HTML element on the page which you want to be the overall container element for the template.</description>
        </tx_templavoila>
        <type>array</type>
        <el type="array">
                     ...ваши поля...
        </el>
    </ROOT>
</T3DataStructure>