Unable to establish a secure connection over FTPS to the Plesk server with the hostname
example.com. One of the following warning messages could be found using the FileZilla FTP client:
The server's certificate is unknown. Please carefully examine the certificate to make sure the server can be trusted
The certificate for securing Plesk is not installed or not valid.
As the certificate used for securing Plesk is also used for FTPS connection to the server, perform the following:
Install/renew a certificate for securing Plesk.
Note: The connection will be secured only if the connection goes to
example.com. If the connection goes to any domain like
domain.tldthen a multidomain SSL certificate must be used for securing Plesk.
For Plesk for Windows check the following article.