The certificate for the remote host could not be validated.

The certificate for the remote host could not be validated: A certificate chain processed, but terminated in a root certificate which is not trusted by the provider.

You created a self-signed certificate which is not trusted by your internal Windows certificate authority (ca).

While using self-signed X.509 certificates for the TLS and transport encryption via HTTPS of the Xtract Universal Server / Service, make sure to insert it into Trusted Root Certification Authorities. 

Finally, you have to select this self-signed certificate within the X.509 Certificate dialogue of the Xtract Universal Server settings, see the following link: