Plugin makes error 500

On page i submited, plugin makes error 500 when i turn it on, if you can check now that page has response code 500

And on the front page in footer when we turn on plugin we get:

document.addEventListener( ‘wpcf7submit’, function( event ) { var reference = Date.now().toString(36) + Math.floor(Math.pow(10, 12) + Math.random() * 9*Math.pow(10, 12)).toString(36); jQuery(‘input[name=”wpcf7cfpdf_hidden_reference”]’).val(reference); }, false );

The page I need help with: [log in to see the link]