How To Fix PO455 - Connection closed after (protocol) error (RC=&1)

SAP Error Message - Details

• Message type: E = Error

• Message class: PO - Spooler message

• Message number: 455

• Message text: Connection closed after (protocol) error (RC=&1)

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

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Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

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Smart SAP Assistant

• What is the cause and solution for SAP error message PO455 - Connection closed after (protocol) error (RC=&1) ?

  The SAP error message "PO455 Connection closed after (protocol) error (RC=&1)" typically indicates that there was a communication issue between the SAP system and an external system or service. This error can occur in various scenarios, such as when using RFC (Remote Function Call), HTTP connections, or other network protocols.
  Causes:
  
  Network Issues: Temporary network disruptions or misconfigurations can lead to connection problems.
  Timeouts: If a request takes too long to process, it may exceed the timeout settings, resulting in a closed connection.
  Protocol Mismatch: The client and server may not be using compatible protocols or versions.
  Resource Limitations: The server may be overloaded or running out of resources, causing it to drop connections.
  Firewall or Security Settings: Firewalls or security settings may block or interrupt the connection.
  Configuration Errors: Incorrect settings in the SAP system or the external system can lead to communication failures.
  
  Solutions:
  
  Check Network Connectivity: Ensure that there are no network issues between the SAP system and the external service. Use tools like ping or traceroute to diagnose connectivity.
  Review Timeout Settings: Check and adjust the timeout settings in both the SAP system and the external service to ensure they are appropriate for the expected response times.
  Verify Protocol Compatibility: Ensure that both systems are using compatible protocols and versions. Update configurations if necessary.
  Monitor System Resources: Check the server's resource usage (CPU, memory, etc.) to ensure it is not overloaded. Consider scaling resources if needed.
  Examine Firewall Rules: Review firewall settings to ensure that they allow the necessary traffic between the systems.
  Check SAP Logs: Look into the SAP system logs (transaction SM21) and the application logs (transaction SLG1) for more detailed error messages that can provide additional context.
  Test with Different Clients: If possible, test the connection using different clients or tools to isolate the issue.
  Consult Documentation: Refer to SAP Notes or documentation related to the specific error message for additional troubleshooting steps or patches.
  
  Related Information:
  
  SAP Notes: Search for relevant SAP Notes in the SAP Support Portal that may address this specific error or provide patches.
  Transaction Codes: Use transaction codes like SM21 (System Log), ST22 (Dump Analysis), and SLG1 (Application Log) to gather more information about the error.
  RFC Connections: If the error is related to RFC, check the RFC destination settings in transaction SM59.
  SAP Community: Engage with the SAP Community forums for insights from other users who may have encountered similar issues.
  
  By following these steps, you should be able to diagnose and resolve the "PO455 Connection closed after (protocol) error" in your SAP environment.