Use transaction SPAU to migrate BAdI implementation &1

What causes this issue?

Migrate the BAdI implementation &1 using transaction SPAU.

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?

To migrate the BAdI implementation into a new BAdI, you must call up
transaction SPAU and select "Migration Objects" on the tab
"Modifications".
You will then find your BAdI implementation under Migration Objects ->
SAP Enhancements. You start the migration by clicking on your BAdI
implementation.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.