This is what I did, it’s working fine, but you may find a better solution.
File: wp-ultimate-csv-importer/index.php on line 47
$get_debug_mode = get_option('wpcsvfreesettings');
if(isset($get_debug_mode['debug_mode']) && $get_debug_mode['debug_mode'] != 'enable_debug' && !WP_DEBUG) {
error_reporting(0);
ini_set('display_errors', 'Off');
}
Thanks