Mat. ledger type cannot be changed as valuation area &1 is live

What causes this issue?

You are trying to change the assignment or characteristic of the
<DS:GLOS.3526B6D7AFAB52B9E10000009B38F974>material ledger category</>
although the material ledger is already productive in valuation area
&V1&.

System Response

The system will not allow the change because it could lead to
inconsistencies in valuation.
The system remakes the original setting.

Error message extract from SAP system. Copyright SAP SE.