3208602 - Error KD136 when settling orders using APP Run Settlement - Actual

When you use APP Run Settlement - Actual to settle orders, error KD136 occurs: Order is not allowed for actual settlement.
Orders with an event-based results analysis key or which are settled by job Production Settlement in Parallel Ledgers cannot by executed by actual settlement.

SAP S/4HANA Cloud

As the error message mentions, orders with an event-based results analysis key or which are settled by job Production Settlement in Parallel Ledgers cannot by executed by actual settlement.

If you are using the Event-Based Production Cost Posting Solution (3F0), then the posting of overhead, WIP and variance values are linked with business events like goods movement, activity confirmation and technically complete manufacturing orders. There are no more period-end activities needed.

Kindly check the order balance in APP Event-Based Order Costs, balance maybe already be cleared as 0.
If there's still balance exists when event-based order is totally delivered(DLV) or technically completed(TECO),
you may check if there's error happen blocked the event-based cost postings.
You can check it following steps in Event-Based Solution - Exception Handling

Event-Based order; 3F0; BEI; Run Settlement - Actual; KO88; RSEBW; KD136. , KBA , CO-OM-OPA , Overhead Orders , Problem