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