How To Fix ME159 - Function modules invoked in wrong sequence

ME159 - Overview

• Message type: E = Error

• Message class: ME - Purchasing: General Messages

• Message number: 159

• Message text: Function modules invoked in wrong sequence

What causes this issue?

The function modules for fully-automatic PO generation have been
invoked in the wrong sequence. The correct sequence is as follows:
1. ME_REFRESH_PO once
2. ME_CREATE_PO_HEADER once
3. ME_CREATE_PO_ITEM n times
4. ME_POST_PO once
If this sequence is not adhered to, data inconsistencies may arise.

How to fix this error?

Please ensure that the function modules are invoked as shown above.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message ME159 - Function modules invoked in wrong sequence ?

  The SAP error message ME159, which states "Function modules invoked in wrong sequence," typically occurs in the context of purchasing documents, such as purchase orders or purchase requisitions. This error indicates that the sequence of function module calls in a program or transaction is not being followed correctly, which can lead to inconsistencies or unexpected behavior in the application.
  Causes:
  
  Incorrect Function Module Sequence: The error often arises when a function module that is expected to be called before another is not executed in the correct order. This can happen due to custom code or enhancements that modify the standard flow.
  Missing Data: If certain prerequisite data is not available or has not been initialized before calling a function module, it can lead to this error.
  Custom Development: If there are custom developments or modifications in the purchasing process, they may not adhere to the expected sequence of function calls.
  User Exits or BAdIs: If