We get the following error when we create an IDOC and post it to SAP R3 system. The IDOC is created in SAP system yet we get the error. As well when we post 1 IDOC 5 IDOCs are created and gives following error as below.
I think you can check ST22 transaction in SAP, to see if there is any dump. That will give you more details. RFC_ERROR_SYSTEM_FAILURE, most likely, means that there is a problem on the SAP side. Also check the RFC traces generated by SAP adapter.
Following is from Sap Help with more detail:-
"When a JCO$Exception has occurred, first of all you can categorize and so localize the cause of the error by the group the exception belongs to. For example, if you see an RFC_ERROR_LOGON_FAILURE error, you know that incorrect logon parameters were used. Whereas if you see an RFC_ERROR_SYSTEM_FAILURE error, you conclude something is wrong with the SAP system you want to connect to, so you have a look at the SAP system. Besides keywords, JCo exceptions return text that is often very helpful for determining the cause of the error.
The above list of exception groups also comprises a column of “possible actions” that help to analyze the failure. If an error has occurred on a lower communication layer, for example an RFC_ERROR_COMMUNICATION or RFC_ERROR_SYSTEM_FAILURE exception, have a look at the dev_jrfc.trc files."