ALE change pointers are not set up correctly

What causes this issue?

The ALE change pointers in the source system are not active.

System Response

The system could not generate the transfer rules, or extract the
request.

How to fix this error?

Activate the change pointer in the source system using transaction
BD61. You may have to reinstall the delta update for the master data
loaded, since changes were not logged while the change pointer was not
active.

Error message extract from SAP system. Copyright SAP SE.