Unexpected string in the output.

[VBog]

wp-includes/media.php in function wp_playlist_scripts( $type )
This code will appear in the output for any function call:

<?php
?>
<!--[if lt IE 9]><script>document.createElement('<?php echo esc_js( $type ) ?>');</script><![endif]-->
<?php

I think that this is not correct. For example, this string appears before json in response of WP REST API request.
​https://bogaiskov.ru/test/wp-json/wp/v2/posts/787

[TimothyBlynJacobs]

Sorry! I can't read numbers apparently.