If you enabled the Sucuri firewall and you are now having issues with VaultPress, this step can usually resolve this. The cause of this is usually because the remote_addr (IP address from which the user is viewing the current page) is being used by VaultPress and that IP belongs to the Sucuri firewall. Installing the Sucuri firewall plugin for WordPress will resolve this in most cases.

You can download it here Sucuri firewall Web Firewall.

If the plugin does not resolve the issue, you can also try adding the following code to your wp-config.php file, right after the “<?php” line: