How To Fix RSTRAN021 - Cannot assign parameter &1 of rule step &2 uniquely

RSTRAN021 - Overview

• Message type: E = Error

• Message class: RSTRAN - Messages for Transformation

• Message number: 021

• Message text: Cannot assign parameter &1 of rule step &2 uniquely

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 RSTRAN021 - Cannot assign parameter &1 of rule step &2 uniquely ?

  The SAP error message RSTRAN021 indicates that there is an issue with the assignment of parameters in a transformation rule. Specifically, it means that the system cannot uniquely assign the parameter specified in the error message to the rule step mentioned. This typically occurs in the context of data transformation processes, such as those used in SAP BW (Business Warehouse) or SAP HANA.
  
  Cause:
  The error can arise due to several reasons:
  
  Duplicate Assignments: The parameter being referenced is assigned to multiple sources or targets in the transformation, leading to ambiguity.
  Incorrect Mapping: The mapping of fields in the transformation might not be set up correctly, causing the system to be unable to determine which source field corresponds to the target field.
  Missing or Incorrect Data: If the data model has been changed (e.g., fields added or removed), it may lead to inconsistencies in the transformation rules.
  Multiple Data Sources: If the transformation is trying to