2460641 - Adding subaccount to SAP Cloud Connector fails due to network issues

• 
  While adding an SAP BTP subaccount to SAP Cloud Connector, or refreshing the subaccount certificate (regardless to SCC version), one of the following errors gets raised:
  
     417 Could not download configuration file — see ''Logs'' for details
  
  OR
  
     500 Failed to sign the cloud connector certificate for subaccount <subaccount>@<region>. Verify configuration and proxy settings — see ''Log And Trace Files'' for details    
  
  
• Upon checking SCC trace for details, an error similar to one of the following is recorded
  
  Preparation of tunnel certificate for <subaccount>@<region> account failed. 
  com.sap.scc.servlets.CriticalSccException: Preparation of tunnel certificate for <subaccount>@<region> account failed.   
        ...
        java.net.ConnectException: Connection timed out
        java.net.ConnectException: Connection refused
        java.net.SocketException: Connection reset
        java.net.ConnectException: Connection reset by peer.
        javax.net.ssl.SSLPeerUnverifiedException: peer not authenticated
        Caused by: java.net.UnknownHostException: proxy
        Unexpected exception while establishing tunnel connection for tunnel ... UnknownHostException
        java.io.IOException: An existing connection was forcibly closed by the remote host
        account failed - host proxy not found.

*Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.

• SAP Cloud Connector release independent;
• SAP Business Technology Platform(BTP).

BTP, Business Technology Platform, Subaccount, 500, 417, certificate, HTTPS, proxy, Cloud Connector, IP address, region host, connection timed out, connection refused, connection reset by peer, peer not authenticated, sub-account, subaccount, tunnel, BTP cockpit, proxy, 3128, squid, HEC proxy, proxy:3128, java.net.UnknownHostException, com.sap.scc.servlets.CriticalSccException , KBA , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , Problem