Salesforce CalloutException - ValidatorException: PKIX path building failed

[Balaji.Dave]

When calling an external service from sales force apex job, following error is received:

"System.CalloutException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target"

My server installed certificate issuer is: Entrust Certification Authority - L1C.

I also checked salesforce trusted certificate list with url:
http://wiki.developerforce.com/page/Outbound_Messaging_SSL_CA_Certificates#addtrustclass1ca

Here I am not sure my certificate issuer is listed or not as I found some certificates listed for Entrust certification with above url but didn't find exact match.

Could you please make me sure that my server installed certificate issuer(Entrust Certification Authority - L1C) is trust certificate for sales force or not and if its trusted then why I am getting this error?

[bob_buzzard]

You need to ask support the certificate question - we are the community and not part of Salesforce.