uguu/rain/template/error_meow.html

<div class="container">
    <div class="row">
        <div class="col s12">
            <div class="card-panel purple lighten-2">
                <div class="card-content white-text">
                    <span class="card-title"><h3>Error!</h3></span>
                    <p>File type not allowed, sorry about that.</p>
                </div>
            </div>
        </div>
    </div>
</div>