2904046 - java.net.UnknownHostException: proxy (SCC to SCP subaccount access issue)

SAP Cloud Connector (SCC) connection to SAP Cloud Platform subaccount fails with the below error:

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#ERROR#com.sap.scc.ui#http-bio-8443-exec-4##
Preparation of tunnel certificate for<<REGION>>account failed.
Caused by: java.net.UnknownHostException: proxy
 at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)

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• SAP Cloud Connector
• Release Independent
• SAP Cloud Platform connectivity

Production ABAP R/3 ERP SRM CRM ERP PPM SEM APO XI PI PORTAL Test development QA KBA On Premise HANA Database SAP Cloud Platform Cloud Connector xsodata On-Premise Access Control HANA DB Cloud to On-Premise HTTPS connection ABAP com.sap.scc.rt SccEndpointValidator OpenJDK Oracle JDK 64-bit SAP JVM 64-bit (recommended) SapMachine , KBA , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , BC-JVM , SAP Java Virtual Machine , BC-NEO-CON , Neo to On-premise Connectivity service , Problem