Is any one connected to java help using SSL ?

Our application Help link does not work when we try to connect to it via SSL (https) it gave us following exception, while there is no problem with http.

I will appreciate it if any one can help me.

Exception ERROR
Got an IOException (sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target)
Parsing failed for null