Gross payment amount NCU &2, payment period &3 not determined

What causes this issue?

For the gross payment document item &V4& the net calculation was
requested to execute the mapping from entitlement amount period to
payment period in order to determine the gross amount for payment period
&V3&.
The involved net calculation unit is represented by
&V1&
&V2&.

System Response

Net Calculation failed for payment period &V3&.

How to fix this error?

Check for additional message indicating the detailed background of the
problem. If required contact your system administrator.

Procedure for System Administrators

The gross payment document item that caused the problem has the ItemID
&V4&.
Check if a customer-specific adjustment caused this problem. If this is
not the case, contact SAP providing the gross payment document version
ID and item ID.

Error message extract from SAP system. Copyright SAP SE.