How To Fix FL226 - Only compatible changes allowed for function module

SAP Error Message - Details

• Message type: E = Error

• Message class: FL - Function Builder messages

• Message number: 226

• Message text: Only compatible changes allowed for function module

What causes this issue?

You attempted to make an incompatible change to a function module that
has been released.

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?

Try to change the interface in a compatible way. For example, you could
add import and changing parameters, provided each has a default value
or is flagged as optional. Tables must also be flagged as optional.
Changes to the reference structures or to the "optional" flags of
existing parameters are not permitted.
If incompatible changes are unavoidable, make a copy of the function
module and continue your work using this copy. You can then make
changes without affecting the existing calls.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message FL226 - Only compatible changes allowed for function module ?

  The SAP error message FL226 ("Only compatible changes allowed for function module") typically occurs when there are incompatible changes made to a function module in SAP. This error is related to the versioning and compatibility rules that SAP enforces to ensure that changes to function modules do not break existing functionality or interfaces.
  Cause:
  The error can be triggered by several scenarios, including but not limited to:
  
  
  Incompatible Changes: Changes that alter the interface of the function module in a way that is not backward compatible. This includes:
  
  Changing the parameter types (e.g., from input to output).
  Changing the number of parameters.
  Changing the data types of existing parameters.
  Removing parameters.
  
  
  
  Transport Issues: If a function module is transported from one system to another and the target system has a different version of the function module, it may lead to this error.
  
  
  Version Conflicts: If there are multiple versions of a function module and an attempt is made to activate a version that is not compatible with the existing one.
  
  
  Solution:
  To resolve the FL226 error, you can take the following steps:
  
  
  Review Changes: Check the changes made to the function module. Ensure that any modifications are compatible with the existing interface. If incompatible changes were made, revert them or adjust them to be compatible.
  
  
  Use Compatible Changes: If you need to make changes, ensure they are compatible. For example:
  
  Add new parameters as optional.
  Do not change existing parameter types or remove parameters.
  
  
  
  Check Transport Requests: If the error is related to transport, ensure that the transport request is correctly configured and that the function module is in a consistent state across systems.
  
  
  Version Management: If you are working with multiple versions, ensure that you are activating the correct version of the function module that is compatible with the rest of your application.
  
  
  Consult Documentation: Refer to SAP documentation or notes related to function module changes and compatibility to understand the specific rules and guidelines.
  
  
  Testing: After making the necessary changes, test the function module thoroughly to ensure that it works as expected without causing any issues in the application.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may provide additional guidance or fixes related to this error.
  Function Module Documentation: Review the documentation for the specific function module to understand its parameters and expected behavior.
  Development Guidelines: Familiarize yourself with SAP's development guidelines regarding function modules and their interfaces to avoid similar issues in the future.
  
  By following these steps, you should be able to resolve the FL226 error and ensure that your function module changes are compatible.