"submit comment" button disappeared

hi Geordi2504,

If you (or anyone who still use this theme) need the fix, you can try to add this code on your Child Theme’s functions.php:

add_filter( 'comment_form_defaults', 'erric_comment_form_args', 20 );
function erric_comment_form_args( $defaults ) {
	$defaults['class_submit']  = 'submit';
	$defaults['name_submit']   = 'submit';
	$defaults['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="%3$s" value="%4$s" />';
	$defaults['submit_field']  = '<p class="form-submit">%1$s %2$s</p>';

	return $defaults;
}

GitHub link:
https://github.com/erricgunawan/live-wire-erric/commit/517ff67e3734182bac3a1283c1a24aaa28c55e48

Tested also on WordPress 4.4 and it still works.

Hope this helps.