I have some problem. You must change this in plugin_dir/js/script.js:
if ( parseInt( $.fn.jquery ) >= 1.7 ) {
$( '#recaptcha_widget_div' ).on( 'input paste change', '#recaptcha_response_field', cleanError );
} else {
$( '#recaptcha_widget_div #recaptcha_response_field' ).live( 'input paste change', cleanError );
}
to
$( '#recaptcha_widget_div' ).on( 'input paste change', '#recaptcha_response_field', cleanError );
It is because this code not correctly work. I use jquery version 1.11.2.
parseInt( 1.11.2 ) >= 1.7 // false