2764049 - SAP Cloud Connector - RFC call exception at action: OPEN_REQUEST - no SAP ErrInfo available

RFC ID is not created for 1 or 2 RFC calls. When 5 or more than 5 RFC calls are pushed in parallel from SAP Cloud Platform (SCP) Java Application to Abap backend for creating Batch master and Purchase order an error message is displayed:

“JCo Exception - Partner signalled an error no SAP error info available”

SAP Cloud Connector's (SCC) ljs_trace show the following entries:

[...]
#ERROR#com.sap.scc.protocol.rfc#RfcPool_1_Thread_176#0x635f3aae#RFC call exception at action: RFC_REQUEST
com.sap.scc.jni.CpicCommunicationException: no SAP ErrInfo available
 at com.sap.scc.jni.CpicConnection.send(Native Method)
 at com.sap.scc.jni.CpicConnection.send(CpicConnection.java:184)
 at com.sap.scc.protocol.rfc.RfcRuntime.queueRfcData(RfcRuntime.java:336)
 at com.sap.scc.protocol.rfc.RfcProtocolProcessor.processBlock(RfcProtocolProcessor.java:196)
 at com.sap.scc.protocol.rfc.RfcProtocolProcessorRunnable.run(RfcProtocolProcessorRunnable.java:130)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 at java.lang.Thread.run(Thread.java:748)
[...]
#ERROR#com.sap.scc.protocol.rfc#RfcPool_1_Thread_176#0x635f3aae#RFC call exception at action: OPEN_REQUEST
com.sap.scc.protocol.rfc.RfcException: Opening connection to null:sapgwnull denied. Expose the system in your Cloud Connector in case it was a valid request.
 at com.sap.scc.protocol.rfc.RfcRuntime.openConnection(RfcRuntime.java:429)
 at com.sap.scc.protocol.rfc.RfcProtocolProcessor.processBlock(RfcProtocolProcessor.java:154)
 at com.sap.scc.protocol.rfc.RfcProtocolProcessorRunnable.run(RfcProtocolProcessorRunnable.java:130)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 at java.lang.Thread.run(Thread.java:748)
[...]

Among Debugged SCP Java Application logs, dev_rfc<X> shows the followings:

[...]
#TRACE#com.sap.conn.jco##anonymous#pool-22-thread-1#na#mbzffdl0q5#digiteauat#web##na#na#na#na#[JCoAPI] exception occurred:
com.sap.conn.jco.JCoException: (102) JCO_ERROR_COMMUNICATION: Partner signaled an error: no SAP ErrInfo available (remote system is <...>)
[...]
Caused by: RfcException raised by system [<...>]:
message: Partner signaled an error: no SAP ErrInfo available
return code: RFC_SYS_EXCEPTION (3)
error group: 102
key: RFC_ERROR_COMMUNICATION
[...]
Caused by: com.sap.conn.rfc.exceptions.RfcGetException: Partner signaled an error: no SAP ErrInfo available
[...]
Caused by:
>RfcIoException:
message: Partner signaled an error: no SAP ErrInfo available
Return code: RFCIO_ERROR_SYSERROR(5)<
[...]

• SAP Cloud Platform Connectivity with RFC Destination
• SAP Cloud Connector
• SAP Cloud Platform Java Application

RFC destination, RfcGetException, Partner signaled an error, no SAP ErrInfo available, RFC_REQUEST, CpicCommunicationException, Opening connection to null, sapgwnull denied , KBA , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , BC-NEO-CON , Neo to On-premise Connectivity service , Problem