How To Fix E9021 - Function &1 is unknown

E9021 - Overview

• Message type: E = Error

• Message class: E9 - General IS-U Error Messages

• Message number: 021

• Message text: Function &1 is unknown

What causes this issue?

You have called a function that the transaction/system does not
recognize.
Either the function is not yet implemented although a menu entry or a
pushbutton exists, or an incorrect function code is transferred to the
program (error in the SAPGUI).

System Response

The system cannot carry out the function.

How to fix this error?

Note the function code from the error message and the screen status
(can be found via <LS>System</> -> <LS>Status</>) and send a problem
message to SAP.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message E9021 - Function &1 is unknown ?

  The SAP error message E9021, which states "Function &1 is unknown," typically indicates that the system is unable to recognize a function module, method, or procedure that is being called in your ABAP code or in a specific transaction. This can occur for several reasons:
  Causes:
  
  Typographical Error: There may be a typo in the function name being called.
  Function Module Not Created: The function module may not exist in the system, possibly due to it not being created or activated.
  Authorization Issues: The user may not have the necessary authorizations to access the function module.
  Transport Issues: If the function module was recently transported from another system, it may not have been imported correctly.
  Namespace Issues: The function might be in a different namespace that is not accessible in the current context.
  Versioning: The function module may have been changed or deleted in a newer version of the software.
  
  Solutions:
  
  Check for Typos: Verify that the function name