Warning message in WordPress 4.7.4

Thank you very much for the plugin. I installed it on WordPress 4.7.4 and getting following warning

Warning: Cannot modify header information – headers already sent by (output started at C:\xampp\htdocs\path_to_my_site\wp-includes\class.wp-styles.php:237) in C:\xampp\htdocs\path_to_my_site\wp-content\plugins\wopzen2\vendor\ZF2\library\Zend\Http\PhpEnvironment\Response.php on line 62

Please help.

Thanks again.