How To Fix WL021 - No implementation found for log '&'

SAP Error Message - Details

• Message type: E = Error

• Message class: WL - Workflow: run-time messages

• Message number: 021

• Message text: No implementation found for log '&'

What causes this issue?

Various protocols can be chosen for sending data in the Web activity.
However, no implementing class could be found for the protocol
currently chosen (number: &V1&).

System Response

The workflow system does not send any data.

How to fix this error?

Enter an appropriate implementation for the protocol.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WL021 - No implementation found for log '&' ?

  Certainly! Here's a detailed explanation for the SAP error message:
  
  SAP Error Message:
  WL021 No implementation found for log '&'
  
  Cause:
  This error occurs when the SAP system tries to process a workflow log entry but cannot find the corresponding implementation (class or function module) that handles the log type specified by the placeholder '&' (which will be replaced by the actual log type in the real message).
  In other words, the workflow runtime is attempting to write or process a workflow log entry of a certain type, but the system does not have an implementation registered or available to handle that log type.
  Common reasons include:
  
  Missing or incomplete workflow component implementations.
  Custom workflow log types introduced but not properly implemented.
  Incomplete transport or system upgrade where some workflow classes or function modules are missing.
  Corrupted or inconsistent workflow repository.
  
  
  Solution:
  
  
  Check the Log Type:
  
  Identify the actual log type that replaces the '&' in the error message. This will give you a clue about which implementation is missing.
  
  
  Verify Workflow Log Implementations:  
  
  Use transaction SWO1 (Business Object Builder) to check the workflow object and its methods.
  Check if the log type corresponds to a standard SAP workflow log or a custom one.
  For custom log types, ensure that the corresponding ABAP class or function module implementing the log is properly created and activated.
  
  
  
  Check Workflow Classes:  
  
  Use transaction SE24 to check if the class implementing the log type exists.
  If missing, implement the required class or restore it from a transport.
  
  
  
  Check Workflow Configuration:  
  
  Use transaction SWI1 (Workflow Log) to see if the workflow logs are being generated correctly.
  Use transaction SWU3 (Workflow Customizing) to check if all workflow customizing steps are completed.
  
  
  
  Apply SAP Notes:  
  
  Search for SAP Notes related to error WL021. Sometimes, SAP provides corrections or patches for missing workflow log implementations.
  
  
  
  System Consistency Check:  
  
  Run workflow consistency checks using transaction SWU_CHECK.
  If inconsistencies are found, correct them accordingly.
  
  
  
  Re-import or Re-activate Workflow Objects:  
  
  If the problem started after a transport or upgrade, try re-importing or re-activating the relevant workflow objects.
  
  
  
  
  Related Information:
  
  
  Transaction Codes:  
  
  SWO1: Business Object Builder  
  SWI1: Workflow Log  
  SWU3: Workflow Customizing  
  SWU_CHECK: Workflow Consistency Check  
  SE24: Class Builder
  
  
  
  SAP Notes:
  
  Search the SAP Support Portal for notes related to "WL021" or "No implementation found for log".
  
  
  Workflow Logs:
  
  Workflow logs are essential for tracking the execution of workflows. Each log type corresponds to a specific handler that formats and processes the log data.
  
  
  Custom Workflow Development:
  
  When creating custom workflow logs, ensure that the corresponding implementation classes or function modules are properly developed and registered.
  
  
  
  If you provide the exact log type (the value replacing '&'), I can help you identify the specific implementation that is missing.
  
  Summary:
  
  The error WL021 indicates a missing implementation for a workflow log type. The solution involves identifying the missing log type, verifying the existence and activation of the corresponding implementation, and correcting any inconsistencies in the workflow repository or customizing.
  
  If you need further assistance, please share the exact log type or the context in which the error occurs.