How To Fix 55021 - Function &1 unknown

SAP Error Message - Details

• Message type: E = Error

• Message class: 55 - Messages for development class EENO

• Message number: 021

• Message text: Function &1 unknown

What causes this issue?

You have called a function that the transaction/system does not know.
Either the function has not been implemented, even though there is a
menu option or a pushbutton, or an incorrect function code has been
transferred to the program (error in SAPGUI).

System Response

The system cannot execute this function.

How to fix this error?

Make a note of the function code (&V1&) stated in the error message and
of the status of the screen (via System->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 55021 - Function &1 unknown ?

  The SAP error message "55021 Function &1 unknown" typically indicates that the system is trying to call a function module or method that does not exist or is not recognized by the system. This can occur for several reasons, including:
  Causes:
  
  Typographical Error: There may be a typo in the function name being called.
  Function Module Not Created: The function module may not have been created or activated in the system.
  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.
  Version Mismatch: The function module may exist in a different version of the software or in a different client.
  
  Solutions:
  
  Check for Typos: Verify that the function name is spelled correctly in the code.
  Function Module Existence: Use transaction SE37 (Function Builder) to check if the function module exists. If it does not, you may need to create it or check with your development team.
  Authorization Check: Ensure that the user has the necessary authorizations to execute the function module. This can be checked in transaction SU53 or by consulting with your security team.
  Transport Check: If the function module was recently transported, check the transport logs to ensure it was imported successfully. You can also check if the function module is in the correct package and has been activated.
  Namespace Verification: Ensure that the function module is in the correct namespace and that your program has access to it.
  System Consistency: If you suspect a version mismatch, check with your Basis team to ensure that all systems are consistent and that the function module is available in the current environment.
  
  Related Information:
  
  Transaction Codes: 
  
  SE37: Function Builder
  SE80: Object Navigator
  SU53: Authorization Check
  
  
  SAP Notes: Search for relevant SAP Notes in the SAP Support Portal that may address specific issues related to this error.
  Debugging: If you have access, you can use the debugger to trace where the error occurs and gather more context about the function call.
  
  If the issue persists after checking these areas, it may be beneficial to consult with your SAP Basis or development team for further investigation.