How To Fix 28123 - Formal parameter &1 in table/function &2 is restrictable

28123 - Overview

• Message type: E = Error

• Message class: 28 - Configuration

• Message number: 123

• Message text: Formal parameter &1 in table/function &2 is restrictable

What causes this issue?

The formal parameters which are used in tables/functions and are
accessed in object dependencies must all be single-value
characteristics. However, formal parameter &V1& for table/function &V2&
is restrictable.

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?

Formal parameter &V1& for table/function &V2& cannot be used in
object dependencies. Correct your entry accordingly.

Error message extract from SAP system. Copyright SAP SE.

28123 - Details

• The SAP error message 28123, which states "Formal parameter &1 in table/function &2 is restrictable," typically occurs in the context of ABAP programming when there is an issue with the definition of a formal parameter in a function module or method. This error indicates that a formal parameter is defined in a way that does not comply with the expected restrictions for that parameter type.
  
  Cause:
  The error can arise due to several reasons:
  
  Parameter Type Mismatch: The formal parameter is defined in a way that it is expected to be non-restrictable, but it is being treated as restrictable.
  Incorrect Definition: The parameter might be defined incorrectly in the function module or method signature.
  Inconsistent Usage: The way the parameter is used within the function or method does not align with its definition.
  
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Parameter Definition: Review the definition of the formal parameter in the function module