How To Fix CMS166 - Error in HTTP Access: &1 &2 &3&4

SAP Error Message - Details

• Message type: E = Error

• Message class: CMS - KPro: Content Management Service

• Message number: 166

• Message text: Error in HTTP Access: &1 &2 &3&4

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.

What else can you do?

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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.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message CMS166 - Error in HTTP Access: &1 &2 &3&4 ?

  The SAP error message CMS166, which indicates "Error in HTTP Access: &1 &2 &3 &4," typically arises when there are issues related to HTTP communication between SAP systems or between an SAP system and an external service. The placeholders (&1, &2, &3, &4) in the error message provide specific details about the nature of the error, such as the HTTP status code, the URL being accessed, or other relevant information.
  Causes:
  
  Network Issues: Problems with network connectivity can prevent HTTP requests from being successfully sent or received.
  Incorrect URL: The URL being accessed may be incorrect or malformed.
  Authentication Issues: If the HTTP request requires authentication, failure to provide valid credentials can lead to access errors.
  Service Unavailability: The target service may be down or not responding.
  Firewall or Proxy Issues: Firewalls or proxy settings may be blocking the HTTP request.
  Configuration Errors: Incorrect configuration in the SAP system or the target service can lead to communication failures.
  
  Solutions:
  
  Check Network Connectivity: Ensure that the network connection between the SAP system and the target service is stable and operational.
  Verify the URL: Double-check the URL being accessed for correctness. Ensure that it is properly formatted and points to the correct endpoint.
  Authentication: If authentication is required, verify that the correct credentials are being used. Check if the authentication method (e.g., Basic, OAuth) is properly configured.
  Service Status: Check the status of the target service to ensure it is up and running. You can try accessing the URL directly from a web browser or using tools like curl or Postman.
  Firewall/Proxy Settings: Review firewall and proxy settings to ensure that they are not blocking the HTTP requests. You may need to whitelist the SAP system or the target service.
  SAP Configuration: Review the configuration settings in the SAP system related to HTTP access, such as the HTTP destination settings in transaction SM59.
  Check Logs: Look at the SAP application logs (transaction SLG1) and the HTTP trace (transaction SMICM) for more detailed error messages that can provide additional context.
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any known issues or patches related to the CMS166 error. SAP frequently updates its knowledge base with solutions for common errors.
  Documentation: Review the official SAP documentation for HTTP communication and configuration to ensure that all settings are correctly applied.
  Community Forums: Consider searching or posting on SAP community forums for additional insights from other users who may have encountered similar issues.
  
  By following these steps, you should be able to diagnose and resolve the CMS166 error in your SAP environment.