CRITICAL Uncaught Error

Hi we receive this error:
CRITICAL Uncaught Error: Call to a member function get() on null in /home/xxxx/public_html/wp-content/plugins/easy-review-reminders/includes/class-err-review-reminders.php:480
Stack trace:
#0 /home/xxxx/public_html/wp-content/plugins/easy-review-reminders/easy-review-reminders.plugin.php(545): ERR_Review_Reminders->errDisplayMessageAfterReviewIsAdded(8996, Object(WP_Comment))
#1 /home/xxxx/public_html/wp-includes/class-wp-hook.php(287): Easy_Review_Reminders->errDisplayMessageAfterReviewIsAdded(8996, Object(WP_Comment))
#2 /home/xxxx/public_html/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array)
#3 /home/xxxx/public_html/wp-includes/plugin.php(478): WP_Hook->do_action(Array)
#4 /home/xxxx/public_html/wp-includes/comment.php(1943): do_action(‘wp_insert_comme…’, 8996, Object(WP_Comment))
#5 /home/xxxx/public_html/wp-content/plugins/woocommerce/includes/class-wc-order.php(1711): wp_insert_comment(Array)
#6 /home/xxxx/public_html/wp-content/plugins/wp-lister-amazon/clas in /home/xxxx/public_html/wp-content/plugins/easy-review-reminders/includes/class-err-review-reminders.php alla riga 480