Hello,
Thank you for choosing our theme and contacting us.
As seen from the error log you have an error thrown from the child theme and it means that you have added some wrong code to its functions.php. In particular, we see there usage of mysql_escape_string that is deprecated and removed in PHP 7.
So try to remove all your customization from child theme or restore original files. Our theme is fully compatible with PHP 7.
Kind Regards
XTemos Studio