FTP Attachments® Setup tab has been deprecated that is giving you an error.
To sign up an FTP Attachments® account with Orektic, Please follow the below steps:
Login to your Salesforce instance
Search for installed Packages in the Quick Search Box
Click on FTP Attachments® Configure button
i.e Setup--> Installed Packages--> FTP Attachments Salesforce.com Base--> Configure