Remarkety uses WordPress's xmlrpc service in order to synchronize data from the backoffice and to generate dynamic coupons if needed.
This file (xmlrpc.php) is sometimes blocked by an .htaccess file to disable access from anywhere due to security concerns. It's possible to enable access only to Remarkety by filtering based on our IP addresses.
Your .htaccess file (the one in your http root directory) might have some other changes, so please be careful when editing it.
Add the following to your .htaccess file (or modify the existing xmlrpc.php entry) in order to allow access to the xmlrpc.php file from Remarkety's IP's only (note: The IP's here may not be updated - modify based on the most recent IP's found here)
deny from all
allow from 18.104.22.168
allow from 22.214.171.124
allow from 126.96.36.199