How To Fix WS661 - Not possible to determine partner without partner schema on header level

SAP Error Message - Details

• Message type: E = Error

• Message class: WS - Supplier Billing Document

• Message number: 661

• Message text: Not possible to determine partner without partner schema on header level

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?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

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 WS661 - Not possible to determine partner without partner schema on header level ?

  Certainly! Here's a detailed explanation of the SAP error message WS661: "Not possible to determine partner without partner schema on header level" including its cause, solution, and related information.
  
  SAP Error Message WS661
  Message Text:
  
  Not possible to determine partner without partner schema on header level
  
  Cause
  This error occurs during the processing of IDocs (Intermediate Documents) in SAP, specifically when the system tries to determine the partner number (logical system or business partner) for an IDoc but cannot find the necessary partner schema at the header level of the IDoc.
  
  The partner schema defines how the system identifies and processes partners in IDoc communication.
  If the partner schema is missing or not maintained for the IDoc type or message type at the header level, SAP cannot determine which partner the IDoc belongs to.
  This typically happens in scenarios involving inbound or outbound IDocs where partner profiles or partner determination settings are incomplete or incorrect.
  
  
  When does it occur?
  
  During inbound IDoc processing, when the system tries to find the partner from the IDoc control record.
  When the partner schema is not maintained in the partner profile (WE20) or in the IDoc processing configuration.
  When the IDoc is processed without a valid partner number or partner type in the control record.
  When the partner schema is missing in the WE42 (Process Code) or WE20 (Partner Profiles) configuration.
  
  
  Solution
  
  
  Check Partner Profiles (Transaction WE20):  
  
  Verify that the partner profile for the relevant partner number and partner type is correctly maintained.
  Ensure that the partner schema is assigned at the header level for the message type and IDoc type.
  If missing, add or correct the partner schema.
  
  
  
  Maintain Partner Schema (Transaction WE41 / WE42):  
  
  Check the process codes and their assignment to partner schemas.
  Ensure that the process code used for the IDoc processing has the correct partner schema assigned.
  
  
  
  Verify IDoc Control Record:  
  
  Check the IDoc control record fields for partner number and partner type.
  Make sure these fields are correctly populated.
  
  
  
  Check Customizing for Partner Determination:  
  
  In some cases, partner determination logic might be customized.
  Review the partner determination procedures and ensure that the partner schema is correctly assigned.
  
  
  
  Reprocess the IDoc:  
  
  After correcting the partner schema or partner profile, reprocess the IDoc using transaction WE19 (Test tool for IDocs) or BD87 (Inbound processing).
  
  
  
  
  Related Information
  
  
  Transactions:
  
  WE20 - Partner Profiles
  WE41 / WE42 - Process Codes
  WE19 - IDoc Test Tool
  BD87 - Reprocess IDocs
  WE02 / WE05 - IDoc Display and Monitoring
  
  
  
  Notes and Documentation:
  
  SAP OSS Notes related to partner schema and IDoc processing errors.
  SAP Help Portal documentation on IDoc partner profiles and partner schema.
  
  
  
  Common Scenarios:
  
  When integrating with external systems via IDocs, partner profiles must be correctly maintained.
  Changes in partner numbers or message types require updates in partner profiles.
  Transport of partner profiles between systems must be handled carefully to avoid missing configurations.
  
  
  
  
  Summary
  
  
  
  Aspect
  Description
  
  
  
  
  Error
  WS661: Not possible to determine partner without partner schema on header level
  
  
  Cause
  Missing or incorrect partner schema in partner profile or process code for the IDoc header
  
  
  Solution
  Maintain partner schema in WE20 and WE42; verify partner number/type in IDoc control record
  
  
  Key Transactions
  WE20, WE41, WE42, WE19, BD87, WE02
  
  
  
  
  If you provide more context (e.g., inbound or outbound scenario, IDoc type, message type), I can help you with more specific steps.