How To Fix WS336 - The application log is already active (internal error)

SAP Error Message - Details

• Message type: E = Error

• Message class: WS - Supplier Billing Document

• Message number: 336

• Message text: The application log is already active (internal error)

What causes this issue?

The application log is already active. Repeat activation is not
possible.

System Response

Processing is terminated.

How to fix this error?

As a rule, this is due to an internal program error.
The external code of the application log already active is &V1&, user
&V2&, report/program &V3&.

Procedure for System Administrators

Please contact SAP.
Function module &V4& was called several times, which is not allowed.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WS336 - The application log is already active (internal error) ?

  SAP Error Message:
  
  WS336 - The application log is already active (internal error)
  
  Cause:
  This error occurs when an attempt is made to start an application log that is already active. In SAP, application logs are used to record messages during processing. The system maintains a status for each log, and if a log is already open (active), trying to open or start it again without closing it first leads to this error.
  Common scenarios causing this error include:
  
  A program or transaction tries to start a log session twice without closing the previous one.
  An internal inconsistency or program error where the log status was not properly reset.
  Parallel processing or multiple calls to the logging function module without proper handling.
  
  
  Explanation:
  
  The application log is managed via function modules like BAL_LOG_CREATE, BAL_LOG_OPEN, and BAL_LOG_CLOSE.
  When a log is started, it is marked as active.
  If the program tries to start the same log again without closing it, the system throws WS336.
  This is an internal safeguard to prevent overlapping or nested logs that could corrupt the log data.
  
  
  Solution:
  
  
  Check the program logic:
  
  Ensure that every call to start or open an application log is paired with a corresponding close.
  Avoid multiple starts of the same log without closing it first.
  Review the code for nested or repeated calls to BAL_LOG_CREATE or BAL_LOG_OPEN.
  
  
  
  Properly close logs:
  
  Use BAL_LOG_CLOSE to close the log after processing is done.
  Make sure that error handling routines also close the log if an exception occurs.
  
  
  
  Debugging:
  
  Use the debugger to trace where the log is started and verify if it is closed properly.
  Check the call stack and program flow to identify multiple starts.
  
  
  
  Check for parallel processing issues:
  
  If the program runs in parallel (e.g., background jobs, parallel tasks), ensure that each process uses separate log handles or unique log identifiers.
  
  
  
  SAP Notes and Patches:
  
  Search for relevant SAP Notes if this error occurs in standard SAP programs or after upgrades.
  Sometimes, this error can be caused by bugs fixed in patches.
  
  
  
  
  Related Information:
  
  
  Function Modules:
  
  BAL_LOG_CREATE – Create a new application log.
  BAL_LOG_OPEN – Open an existing application log.
  BAL_LOG_CLOSE – Close the application log.
  BAL_LOG_DELETE – Delete an application log.
  
  
  
  Transaction SLG1:
  
  Used to display application logs.
  Can be used to check if logs are left open or to analyze logs related to the error.
  
  
  
  SAP Help:
  
  Application Log documentation: SAP Help Portal - Application Log
  
  
  
  Common SAP Notes:
  
  Check SAP Notes related to WS336 or application log errors for your SAP version.
  
  
  
  
  Summary:
  
  Cause: Attempt to start an application log that is already active.
  Solution: Ensure logs are properly closed before starting again; review and correct program logic.
  Check: Use debugging and transaction SLG1 to analyze logs and program flow.
  
  If you provide the context or program where this error occurs, I can help with more specific guidance.