It would be possible to see more information that is causing the ERROR 500 in the Essential Grid setting.
Perhaps the PHP memory limit of your local setting is maxed out.
To have more details information about the cause, find the wp-config.php file then search for the line
define( 'WP_DEBUG', false ); and set it to
Go back to the Wordpress admin's Essential Grid setting and you should be able to see some error messages.
If it mentions about the memory being exhausted, we'd recommend that you increase your memory allocated to PHP if you haven't done so already. To increase it, please edit your wp-config.php file and insert these lines:
define( 'WP_MEMORY_LIMIT', '256M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );
You can add it before the line
/*That's all, stop editing! Happy Blogging. */
In case you are getting a different message and you're not able to get it sorted, please post it here so that we can provide further suggestions.
Hope this helps.