How To Fix RSAR780 - Error in the prefix determination. Start value & is unknown

RSAR780 - Overview

• Message type: E = Error

• Message class: RSAR - Data Transfer and Metadata Maintenance

• Message number: 780

• Message text: Error in the prefix determination. Start value & is unknown

What causes this issue?

Incorrect call of the prefix determination for the transfer structure of
the source system. The prefix start value &V1& is not one of the
allowed values (A-Z, 0-9).

System Response

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

How to fix this error?

Using the error number (ID) search for relevant notes in the SAP Support
Portal.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message RSAR780 - Error in the prefix determination. Start value & is unknown ?

  The SAP error message RSAR780, which states "Error in the prefix determination. Start value & is unknown," typically occurs in the context of SAP BW (Business Warehouse) when there is an issue with the data source or the data extraction process. This error is related to the extraction of data from a source system, and it indicates that the system is unable to determine the prefix for a certain data object.
  Causes:
  
  Missing or Incorrect Prefix Configuration: The prefix for the data source may not be defined correctly in the system, or it may be missing entirely.
  Data Source Issues: The data source from which you are trying to extract data may not be properly configured or may not exist.
  Transport Issues: If the data source was recently transported from another system, there may be inconsistencies or missing configurations.
  Authorization Issues: The user executing the extraction may not have the necessary authorizations to access the