Execute period-end billing first

What causes this issue?

You wish to bill the contract starting from &v1&. A period-end billing
order exists for the contract for the period from &v2& to &v3&. You
must execute period-end billing before you can excute other billings
for the contract.

System Response

How to fix this error?

Execute period-end billing for the period-end billing order with
scheduled billing date &v4&.
Execute other billing for the contract.
Note the <DS:DE.ENDPRIO>control option</> for the priority of the
period-end billing in the <DS:GLOS.rate_category>rate category</>.

Error message extract from SAP system. Copyright SAP SE.