Hi,
This fix only for 2.1.3
Edit
../wp-content/plugins/js-support-ticket/js-support-ticket.php
Find
add_filter( 'upgrader_pre_download', 'filter_upgrader_pre_download', 10, 3 );
Replace with
//add_filter( 'upgrader_pre_download', 'filter_upgrader_pre_download', 10, 3 );