Babylon.js/Viewer/assets/templates/default/error.html

<style>
    .narrator-readable-text {
        border: none;
        background: none;
        color: inherit;
        border: none;
        padding: 0;
        font: inherit;
        cursor: pointer;
        outline: inherit;
    }
</style>

<!-- Accessibility button that a screen narrator will read -->
<button class="narrator-readable-text">Error loading the model</button>