SAP Knowledge Base Article - Preview

1939124 - Connection closed (no data) error during connection test to an external program


  • In the external RFC trace with the file name format rfc<pid>_<tid>.trc there is the error message Error ab_RfcSetHeader> invalid compression value 5 received.
  • The header of the external RFC trace shows that the RFC library used by the external program is non-unicode RFC-VER nU.
  • The connection test to an external program in SM59 fails with connection closed (no data).



  • SAP NetWeaver
  • SAP Web Application Server for SAP S/4 HANA
  • ABAP PLATFORM - Application Server ABAP
  • Unicode ABAP system, non-unicode RFC library on the external (non-ABAP) side


TCP/IP destination connection closed, RFC library, Communication Between SAP Systems and Other SAP or Non-SAP Systems, classic RFC library is not supported by SAP since 2016, RFCSTD , KBA , BC-MID-RFC-SDK , NetWeaver RFC SDK , Problem

About this page

This is a preview of a SAP Knowledge Base Article. Click more to access the full version on SAP for Me (Login required).

Search for additional results

Visit SAP Support Portal's SAP Notes and KBA Search.