Document split necessitates recreation of ledger &

What causes this issue?

You want to activate the document split for ledger &V1&. However,
ledger &V1& already stores data. Since the document split creates and
manages process chains (for example, an invoice and the related
payment) you must have posted all of the data stored in the ledger
using the document split. An invoice without document split and a
payment with active document split would lead to inconsistent data in
the system.

System Response

The system does not activate the document split.

How to fix this error?

If you want to activate the document split, you have to first delete
the data from ledger &V1& and recreate it. If you are unsure of how to
proceed, contact SAP.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.