How To Fix W_001 - Internal error when calling a function module

SAP Error Message - Details

• Message type: E = Error

• Message class: W_ - Upload CRM -> R3 BOMs / Structured Materials

• Message number: 001

• Message text: Internal error when calling a function module

What causes this issue?

When a function module was called up, an error was recognised, and an
exception was triggered.

System Response

Processing cannot be carried out.

How to fix this error?

This is a system error. Inform your system administrator. The error has
occurred in function module &V1&. The return value was &V2&.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message W_001 - Internal error when calling a function module ?

  SAP Error Message:
  
  W_001 Internal error when calling a function module
  
  Cause
  This warning message typically occurs when there is an internal error during the execution of a remote function call (RFC) or a function module call within SAP. The causes can vary, but common reasons include:
  
  Incorrect or inconsistent data passed to the function module.  
  Authorization issues preventing the function module from executing properly.  
  Missing or incorrect parameters in the function call.  
  System or communication errors during RFC calls (e.g., network issues, system load).  
  Function module itself has a bug or is not properly implemented.  
  Incompatible SAP kernel or patch level causing unexpected behavior.  
  Buffer or memory issues in the SAP system.  
  
  
  Solution
  To resolve the W_001 Internal error when calling a function module warning, follow these steps:
  
  
  Check the exact function module name and parameters:  
  
  Verify that the function module is called with the correct parameters and data types.  
  Ensure no mandatory parameters are missing or incorrectly filled.
  
  
  
  Review authorization:  
  
  Check if the user executing the function module has the necessary authorizations.  
  Use transaction SU53 immediately after the error to check for authorization failures.
  
  
  
  Check system logs and dumps:  
  
  Use transaction ST22 to look for any short dumps related to the function module call.  
  Check system log (SM21) for related errors or warnings.
  
  
  
  Test the function module independently:  
  
  Use transaction SE37 to test the function module with the same parameters to see if it runs without error.
  
  
  
  Check RFC destinations:  
  
  If the function module is called remotely, verify the RFC destination in SM59.  
  Test the connection and check for network or communication issues.
  
  
  
  Update or patch the system:  
  
  Ensure the SAP kernel and support packages are up to date.  
  Sometimes internal errors are fixed in newer patches.
  
  
  
  Debug the function module:  
  
  If you have development access, debug the function module to identify where the internal error occurs.
  
  
  
  Consult SAP Notes:  
  
  Search the SAP Support Portal for notes related to the specific function module or error message.  
  SAP Notes often provide fixes or workarounds.
  
  
  
  
  Related Information
  
  
  Transaction Codes:  
  
  SE37 — Function Builder (to test/debug function modules)  
  ST22 — ABAP Runtime Error Analysis  
  SM21 — System Log  
  SM59 — RFC Destinations  
  SU53 — Authorization Check
  
  
  
  SAP Notes:  
  
  Search for notes with keywords like "W_001 Internal error", the function module name, or related error details.
  
  
  
  RFC Troubleshooting:  
  
  If the error occurs during an RFC call, check network connectivity, user authorizations, and RFC destination configuration.
  
  
  
  
  Summary
  The W_001 Internal error when calling a function module warning indicates an internal problem during the function module execution, often due to incorrect parameters, authorization issues, or system errors. Careful analysis of parameters, authorizations, system logs, and testing the function module independently usually helps identify and resolve the root cause. If necessary, debugging and consulting SAP Notes are recommended.
  
  If you provide the exact function module name or context where this error occurs, I can help with more specific guidance.