How To Fix APPL_PROC_HUB_PR020 - Could not connect to the back-end system &1

SAP Error Message - Details

• Message type: E = Error

• Message class: APPL_PROC_HUB_PR - Message Class for Purchase Requisition Extraction

• Message number: 020

• Message text: Could not connect to the back-end system &1

What causes this issue?

Could not connect to the back-end system <(>&<)>1. The attempt to
restart the job has failed twice.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message APPL_PROC_HUB_PR020 - Could not connect to the back-end system &1 ?

  The SAP error message APPL_PROC_HUB_PR020 indicates that there is a problem with connecting to the back-end system specified in the error message. This can occur in various scenarios, such as when using SAP Process Integration (PI), SAP Process Orchestration (PO), or when trying to access a back-end system from a front-end application.
  Causes:
  
  Network Issues: There may be network connectivity problems between the front-end and back-end systems.
  Configuration Errors: Incorrect configuration settings in the SAP system or in the middleware (like PI/PO) can lead to connection failures.
  Service Unavailability: The back-end system may be down or not reachable due to maintenance or other issues.
  Authentication Problems: Issues with user credentials or authorization can prevent successful connections.
  Firewall Restrictions: Firewalls or security settings may be blocking the connection to the back-end system.
  Incorrect System Alias: The system alias used to connect to the back-end may be incorrect or not properly defined.
  
  Solutions:
  
  Check Network Connectivity: Ensure that the network connection between the systems is stable and operational. You can use tools like ping or traceroute to diagnose connectivity issues.
  Review Configuration Settings: Verify the configuration settings in the SAP system and middleware. Ensure that the connection parameters (like host, port, and service) are correctly set.
  Check Back-End System Status: Confirm that the back-end system is up and running. You can check the system logs or contact the system administrator for status updates.
  Validate User Credentials: Ensure that the user credentials used for the connection are correct and that the user has the necessary authorizations.
  Inspect Firewall Settings: Check if any firewalls or security settings are blocking the connection. You may need to work with your network/security team to allow the necessary traffic.
  Verify System Alias: Ensure that the system alias used in the connection is correctly defined in the SAP system. You can check this in transaction SM59 (RFC Destinations).
  
  Related Information:
  
  Transaction Codes: 
  
  SM59: To check and configure RFC destinations.
  SICF: To check the status of HTTP services.
  ST22: To analyze dumps that may provide more context on the error.
  
  
  Logs: Check the application logs (transaction SLG1) for more detailed error messages that may provide additional context.
  SAP Notes: Search for relevant SAP Notes in the SAP Support Portal that may address specific issues related to this error message.
  
  If the issue persists after checking the above points, it may be beneficial to engage with SAP support for further assistance.