Wing FTP Software

I am struggling to get a valid SSL certificate installed. Everything goes through but when I visit the site I get a "This CA Root Certificate is not Trusted. To enable trust, install this certificate in the Trusted Root Certification Authorities store."

I have tried using the built in SSL generator and also purchasing one but although they show that the certificate is within date I still get this message

What am i doing wrong ?

Maybe your SSL cert is not correct, please generate a standard PEM format cert, like this: https://bbs.wftpserver.com/viewtopic.php?t=54