How To Fix KG866 - An entry with the same source data already exists

KG866 - Overview

• Message type: E = Error

• Message class: KG - CO-PA Planning

• Message number: 866

• Message text: An entry with the same source data already exists

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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Smart SAP Assistant

• What is the cause and solution for SAP error message KG866 - An entry with the same source data already exists ?

  The SAP error message KG866 ("An entry with the same source data already exists") typically occurs in the context of the Controlling (CO) module, particularly when dealing with cost center planning, internal orders, or other planning-related activities. This error indicates that there is an attempt to create or modify a planning entry that already exists in the system with the same key data.
  
  Cause:
  
  Duplicate Entries: The most common cause of this error is that there is already an existing entry in the planning table for the same cost center, period, and other relevant fields.
  Incorrect Data Entry: Sometimes, the data being entered may inadvertently match an existing entry due to incorrect or incomplete data entry.
  Data Migration Issues: If data has been migrated from another system or from a previous version of SAP, there may be duplicate entries that were not cleaned up.
  Concurrent Users: If multiple users are trying to enter or modify