Select a cash pool whose service provider is "Bank".

What causes this issue?

You have assigned this bank account as a subaccount of a cash pool. By
assigning the bank account as the header account of another cash pool,
the second cash pool becomes the child cash pool of the first one, and
the bank account serves both as the header account of the child cash
pool and a subaccount of the parent cash pool. In a multi-level cash
pool like this, only cash pools with the service provider <LS>Bank
</>can be defined as child cash pools. They are the zero-balancing cash
pools operated by banks and their balances will be concentrated to the
header pool at day end.

System Response

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

How to fix this error?

Select a cash pool whose service provider is <LS>Bank</>.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.