How To Fix FDT_EXPRESSIONS449 - &1 is a reference variable. Those can not be handled by BRFplus

SAP Error Message - Details

• Message type: E = Error

• Message class: FDT_EXPRESSIONS - Formula & Derivation Tool: Expressions

• Message number: 449

• Message text: &1 is a reference variable. Those can not be handled by BRFplus

What causes this issue?

In the container of the workflow or event associated with the current
BRFplus action, input field &v1& is defined as a reference variable.
However, BRFplus cannot resolve such references and therefore cannot
determine the type of that input field.

System Response

BRFplus ignores the input field in the event container or workflow
container. However, if input for the field is mandatory, the event or
workflow cannot be used within BRFplus because there is no way to
provide any input for the mandatory field.

How to fix this error?

The only way to resolve this issue is to replace the reference variable
by a static type assignment. If this is not possible, the workflow or
event cannot be associated with an BRFplus action.

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 FDT_EXPRESSIONS449 - &1 is a reference variable. Those can not be handled by BRFplus ?

  The SAP error message FDT_EXPRESSIONS449 indicates that you are trying to use a reference variable in a context where it is not supported by BRFplus (Business Rules Framework plus). This typically occurs when you are attempting to use a reference variable in a rule or expression that does not allow for such variables.
  Cause:
  
  Reference Variable Usage: The error arises when a reference variable (which points to another variable or object) is used in a BRFplus expression or rule where only value variables are permitted.
  Incompatibility: BRFplus has specific requirements and limitations regarding the types of variables that can be used in certain contexts. Reference variables are not directly usable in expressions that expect concrete values.
  
  Solution:
  
  Check Variable Types: Review the variables being used in your BRFplus rules or expressions. Ensure that you are using value variables instead of reference variables where required.
  Modify Expressions: If you need to use a reference variable, consider restructuring your logic to avoid using it in the context that generates the error. You may need to extract the value from the reference variable and use that value instead.
  Use Value Variables: If possible, replace the reference variable with a value variable that holds the actual data you need for your calculations or conditions.
  Consult Documentation: Refer to the official SAP documentation for BRFplus to understand the limitations and best practices regarding variable usage.
  
  Related Information:
  
  BRFplus Documentation: SAP provides comprehensive documentation on BRFplus, including guidelines on variable types and their usage.
  SAP Community: Engaging with the SAP Community can provide insights from other users who may have encountered similar issues.
  Debugging: Use the debugging tools available in BRFplus to trace the execution of your rules and identify where the reference variable is being incorrectly used.
  
  By addressing the use of reference variables and ensuring that only compatible variable types are used in your BRFplus expressions, you should be able to resolve the error message FDT_EXPRESSIONS449.