How To Fix WL109 - Expression & has data type reference & and not &

SAP Error Message - Details

• Message type: E = Error

• Message class: WL - Workflow: run-time messages

• Message number: 109

• Message text: Expression & has data type reference & and not &

What causes this issue?

According to the container definition, expression &v1& references an
object of type &v2&. However, the container element to which this
expression is allocated is defined with ABAP Dictionary reference &v3&.

System Response

This allocation is not permitted.

How to fix this error?

Change the allocation.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WL109 - Expression & has data type reference & and not & ?

  The SAP error message WL109 indicates a type mismatch in an expression. Specifically, it means that the expression you are trying to evaluate has a data type that is a reference type, but the expected data type is different. This error typically occurs in ABAP (Advanced Business Application Programming) when you are working with data types and trying to assign or compare values that are not compatible.
  Cause:
  The error can occur due to several reasons:
  
  Type Mismatch: You are trying to use a reference type (like a reference to an object or a structure) in a context where a different type (like a value type) is expected.
  Incorrect Variable Declaration: The variable you are using may not be declared correctly, or you may be using a reference variable where a value variable is expected.
  Improper Use of Data Types: You might be trying to perform operations or comparisons between incompatible data types.
  
  Solution:
  To resolve the WL109 error, you can take the following steps:
  
  
  Check Variable Declarations: Ensure that all variables are declared with the correct data types. If you are using reference types, make sure they are being used in the right context.
  
  
  Type Casting: If you need to use a reference type in a context that requires a value type, consider using type casting or converting the reference type to the appropriate value type.
  
  
  Review Expressions: Look at the expression that is causing the error. Ensure that all parts of the expression are compatible in terms of data types.
  
  
  Debugging: Use debugging tools to step through the code and inspect the data types of the variables involved in the expression. This can help you identify where the mismatch is occurring.
  
  
  Consult Documentation: Refer to the SAP documentation for the specific data types you are working with to understand their properties and how they can be used.
  
  
  Related Information:
  
  ABAP Data Types: Familiarize yourself with the different data types in ABAP, including value types (like integers, strings) and reference types (like objects, internal tables).
  Type Checking: ABAP has strict type checking, so it is essential to ensure that the types match when performing operations.
  SAP Notes: Check SAP Notes for any known issues or additional guidance related to the WL109 error.
  
  By following these steps, you should be able to identify and resolve the cause of the WL109 error in your SAP ABAP code.