How To Fix 55401 - Internal error: message classification &1, parentheses

SAP Error Message - Details

• Message type: E = Error

• Message class: 55 - Messages for development class EENO

• Message number: 401

• Message text: Internal error: message classification &1, parentheses

What causes this issue?

Message classification (&V1&) for the IS-U message object has an
invalid format. This is a program error that can only be rectified by
SAP.

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?

Note the following:
transaction
entries leading to the error
message text
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 55401 - Internal error: message classification &1, parentheses ?

  The SAP error message 55401, which states "Internal error: message classification &1, parentheses," typically indicates an internal inconsistency or issue within the SAP system. This error can arise from various underlying causes, including:
  Causes:
  
  Data Inconsistency: There may be inconsistencies in the data being processed, such as missing or malformed entries.
  Configuration Issues: Incorrect configuration settings in the system can lead to unexpected behavior and errors.
  Custom Code: If there are custom developments or enhancements in the system, they might not be handling certain scenarios correctly.
  System Bugs: There could be bugs in the SAP software version you are using, which may have been addressed in later patches or updates.
  
  Solutions:
  
  Check for Data Issues: Review the data being processed when the error occurs. Look for any anomalies or inconsistencies that could be causing the issue.
  Review Configuration: Ensure that all relevant configurations are set up correctly. This includes checking transaction codes, message classes, and any related settings.
  Debugging: If you have access to the ABAP debugger, you can try to trace the execution path leading to the error. This may help identify the specific point of failure.
  Check SAP Notes: Search the SAP Support Portal for any relevant SAP Notes that might address this specific error. SAP frequently releases notes that provide fixes or workarounds for known issues.
  Update System: If the error is due to a known bug, consider applying the latest support packages or patches for your SAP system.
  Contact SAP Support: If the issue persists and you cannot find a resolution, consider reaching out to SAP Support for assistance. Provide them with detailed information about the error, including the context in which it occurs.
  
  Related Information:
  
  Transaction Codes: Depending on where the error occurs, you may want to check transaction codes related to the specific module or functionality you are working with.
  Logs and Traces: Review system logs (SM21) and application logs (SLG1) for additional context around the error.
  User Forums: Check SAP community forums or other user groups for similar issues and potential solutions shared by other users.
  
  By following these steps, you should be able to diagnose and potentially resolve the SAP error message 55401.