What does the “Warning: Failed to verify the authenticity of this certificate. No assertions can be made of the origin or validity of the code.” mean?
A certificate can only be trusted if you trust the certificate authority (CAs) that created the certificate. Java Web Start is shipping with a set of trusted root certificates of the most common CAs. If you sign your application with a certificate that is authorized by someone and is not in the set of trusted root certificates, you will see the above warning message. This will, for example, happen if you use a self-signed certificate.