Resources/Private/Templates/Modules/Message.html
<html xmlns:f="http://typo3.org/ns/TYPO3/CMS/Fluid/ViewHelpers" data-namespace-typo3-fluid="true">
<f:layout name="Modules"/>
/**
* Entry point for the rendering of a message.
*/
<f:section name="main">
<div class="typo3-adminPanel-message typo3-adminPanel-message-{severity}">
<div class="typo3-adminPanel-message-text">
{text}
</div>
</div>
</f:section>
</html>