Due date &1: total cash flow amount differs from ISR amount(see long text

What causes this issue?

The invoice amount does not agree with the balance of the cash flow
items for the due date.

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?

Correct the amount.
If you want to allow the difference, then set the
<DS:DE.REXCRAESRREFACCEPTDIFFAMOUNT> Allow Difference Between ISR Amount
and Cash Flow Balance</> indicator. Or create a one-time condition by
choosing <ZK>Condition</>.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.