Issue while getting the contacts from Yahoo API using Socialauth

[11/7/12 1:36:04:421 IST] 0000004d RequestProces W org.apache.struts.action.RequestProcessor processException Unhandled Exception thrown: class org.brickred.socialauth.exception.SocialAuthException
[11/7/12 1:36:04:531 IST] 0000004d servlet       E com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0068E: Uncaught exception created in one of the service methods of the servlet action in application YahooExtAPIEAR. Exception created : javax.servlet.ServletException: org.brickred.socialauth.exception.SocialAuthException: javax.net.ssl.SSLHandshakeException: com.ibm.jsse2.util.g: PKIX path building failed: java.security.cert.CertPathBuilderException: PKIXCertPathBuilderImpl could not build a valid CertPath.; internal cause is:
    java.security.cert.CertPathValidatorException: The certificate issued by OU=Equifax Secure Certificate Authority, O=Equifax, C=US is not trusted; internal cause is:
    java.security.cert.CertPathValidatorException: Certificate chaining errorOR you have not set any scope while registering your application. You will have to select atlest read public profile scope while registering your application
    at org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:523)
    at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421)
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
    at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:718)

Please help me when this error will get