AdminTinymce3FileldsSection.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-->

<sections xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:noNamespaceSchemaLocation="urn:magento:mftf:Page/etc/SectionObject.xsd">
    <section name="ProductWYSIWYGSection">
        <element name="Tinymce3MSG" type="button" selector=".admin__field-error"/>
    </section>
    <section name="TinyMCESection">
        <element name="TinyMCE3" type="text" selector="#cms_page_form_content_tbl"/>
        <element name="InsertImageBtnTinyMCE3" type="button" selector="#cms_page_form_content_image"/>
    </section>
    <section name="NewsletterWYSIWYGSection">
        <element name="TinyMCE3" type="text" selector="#cms_page_form_content_tbl"/>
    </section>
</sections>