How To Fix WD288 - Expression '&' has an invalid type or reference

WD288 - Overview

• Message type: E = Error

• Message class: WD - Workflow definition

• Message number: 288

• Message text: Expression '&' has an invalid type or reference

What causes this issue?

You have entered the expression &V1&. This has a data type reference
that cannot accept organizational objects.

System Response

The expression is not permitted by the system.

How to fix this error?

Use an expression that can accept organizational objects.

Procedure for System Administrators

Use an ABAP Dictionary reference that refers to the domain
<AB>HROBJEC_14</> as data type reference for the expression.

Error message extract from SAP system. Copyright SAP SE.

WD288 - Details

• The SAP error message:
  WD288 Expression '&' has an invalid type or reference
  typically occurs in the context of Web Dynpro ABAP development, specifically when there is an issue with an expression used in the UI element properties, context bindings, or in the code where an expression is evaluated.
  
  Cause
  
  The error indicates that the expression containing the character & (ampersand) is invalid due to:
  Incorrect syntax in the expression.
  Use of an invalid or undefined reference (e.g., a context attribute or variable that does not exist or is not accessible).
  The expression is expected to be of a certain data type, but the actual type is incompatible.
  The & character is often used in expressions for concatenation or as a placeholder, but if used incorrectly, it causes this error.
  
  
  
  In Web Dynpro ABAP, expressions are used in property bindings or in the IF_WD_CONTEXT_ELEMENT~GET_ATTRIBUTE method, and the expression parser expects valid references and types.
  
  Typical Scenarios
  
  Using & in an expression