The execution failed. Please check error.log
Please contact the author of your purchased theme, theme author will assist you.
How to contact an author to get support or for any technical query:
Also you can check the theme documentation hopefully you will get necessary help.
You can use WP Debugging plugin to check the error or edit wp-config.php and set WP_DEBUG as true.
define( ‘WP_DEBUG’, true );
Maybe, your hosting provider stopped a function. You can make sure in that way before calling theme author.