How To Fix WS660 - Target partner schema &1 has fewer partner roles than source schema &2

SAP Error Message - Details

• Message type: E = Error

• Message class: WS - Supplier Billing Document

• Message number: 660

• Message text: Target partner schema &1 has fewer partner roles than source schema &2

What causes this issue?

In the target partner schema &V1&, partner roles intended for the source
schema &V2& are missing. This means that not all partners can be copied
and cancellation documents deviate from the source documents.

System Response

The document &V3& cannot be cancelled.

How to fix this error?

Adjust partner schemas &V1& and &V2& so they match. Ensure that partner
schema &V1& contains all partner roles of partner schema &V2&.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WS660 - Target partner schema &1 has fewer partner roles than source schema &2 ?

  The SAP error message:
  WS660 Target partner schema &1 has fewer partner roles than source schema &2
  
  Meaning / Cause
  This error occurs during the configuration or processing of IDoc partner profiles in SAP ALE/EDI. It indicates that the target partner schema (the schema assigned to the receiving partner) has fewer partner roles defined than the source partner schema (the schema assigned to the sending partner).
  In other words, the partner schema on the receiving side does not include all the partner roles that exist in the sending side's partner schema. Since partner roles define the roles a partner can play in message exchange (e.g., LS - Logical System, KU - Customer, LI - Vendor, etc.), having fewer roles in the target schema means the system cannot properly map or process all the roles expected from the source schema.
  
  When does it occur?
  
  During IDoc processing or partner profile configuration.
  When assigning or comparing partner schemas in