dev_jco_rfc.trc is generated with error message as shown below (example error message) if the SAP user does not have access to the SAP function SYSTEM_RESET_RFC_SERVER.

*** Error file opened at 20190320 171752 Central European Time Rel. 3.0.19 (2018-12-03) [721.1120]
Error:  >Wed Mar 20 17:17:52,660<    >RfcGetException (rc=7) message: No RFC authorization for function module SYSTEM_RESET_RFC_SERVER.
<RfcGetException
Error: [1] >Wed Mar 20 17:17:53,005<    RfcException raised by system [ZE1|sapze10|62]:
        message: Handle close pending
        return code: RFC_CLOSED (6)
        error group: 109
        key: RFC_ERROR_CANCELLED"

According to SAP jrfc trace, as of SAP JCo version 3.0.19, SAP function SYSTEM_RESET_RFC_SERVER is called by SAP JCo internally against every inbound RFC invocations including the inbound RFC invocations for fetching the IDoc/RFC/BAPI schemas or posting IDoc messages to SAP via inbound tRFC invocations or the inbound bi-way RFC/BAPI invocations.

Access of SAP function SYSTEM_RESET_RFC_SERVER is needed for the SAP user used on the SAP Connection Resource

All Supported Platforms

The access of SAP function SYSTEM_RESET_RFC_SERVER is needed for the SAP user assigned on the SAP Connection Resource.

SAP, SAP User, SAP Function, Function Access