3588639 - Error "An error occurred, kindly retry" while generating Token for Datasphere, or no system nodes found when connecting to Datasphere

• Error "An error occurred, kindly retry" while generating token for Datasphere in BI 4.3 SP3 and above :
  
• APS STS traces contains below details.

  OAuthImpl::getAuthorizationGrantType
  Custom properties empty.
  OAuthImpl.getAuthorizationGrantType valret=eAuthorizationCode
  OAuthImpl::getAuthorizationGrantType: 00.000
  Process HTTP request : https://<HOSTNAME>/oauth/token
  Process HTTP request : https://<HOSTNAME>/oauth/token: 00.000
  OAuthImpl::generateRefreshToken: 00.094
  STS: An unexpected error has occurred (FWM 02004) sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
  com.crystaldecisions.sdk.exception.SDKException$Unexpected: An unexpected error has occurred (FWM 02004)
  cause:javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
  detail:An unexpected error has occurred (FWM 02004) sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target 

• In some cases, the below errors might be seen in the DSL bridge traces, for example when connecting to Datasphere in web intelligence
  com.businessobjects.mds.olap.protocol.sap.ip.bi.conv.dac.res.ina.java.execptions.INAConnectionException: Unknown Error
  Caused by: com.businessobjects.mds.olap.protocol.sap.ip.bi.conv.dac.res.ina.java.execptions.BicsHttpInaRuntimeException: Unexpected exception
  Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
  Exception caught in SL Service: No system nodes found on specified system types. 

• SAP BusinessObjects Business Intelligence Platform 4.3 SP3 and above.

oauth, datasphere, firewall, network, token, FWM 02004, STS , KBA , BI-BIP-AUT , Authentication, ActiveDirectory, LDAP, SSO, Vintela , Problem