Account assignment model & unknown

What causes this issue?

Account assignment model &V1& not recognized.

System Response

The model can not be used.

How to fix this error?

If you want to create the model, choose <LS>Accounting->Financial
Accounting->General Ledger, Document entry -> Reference
documents->Account assignment model</> or start the function directly:
<DS:TRAN.FKMT>Proceed</>

Error message extract from SAP system. Copyright SAP SE.