Transfer is not possible as installment plan &1 exists

What causes this issue?

No transfer can be made to contract account &V3& for business partner
&V2&, as installment plan &V1& exists. This is not permitted when you
are using official document numbering in FI-CA.

System Response

Processing is terminated.

How to fix this error?

Deactivate installment plan &3 and then restart the transfer.

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.