Amount &1 &2 could not be assigned

What causes this issue?

The clearing algorithm for clearing type &v3& could not determine a
meaningful clearing proposal. In such a case, the clearing control
configuration is such that no automatic posting on account of the
payment amount takes place.

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?

The items that you want to clear can be processed manually. During
incoming payment processing you can also check whether the selection
criteria apply for the open items. If this is not the case, you can
execute the posting of the payment with new selection criteria.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.