WZone Lite : The loopback request to your site failed

Hi, I am planning to buy the plugin, but I am still having problems making Lite version work.
My site’s health check plugin is giving me error below –

The loopback request to your site failed, this may prevent WP_Cron from working, along with theme and plugin editors.<br>Error encountered: (0) cURL error 28: Operation timed out after 10000 milliseconds with 0 bytes received

Thanks,