3390338 - Error C+831 raised in post closing step of atual costing run

When trying to execute 'Post Closing' step of actual costing run, error C+831 "You must first allow closing entries for period &1 / &2" raised.

SAP S/4HANA Cloud Public Edition

There's a lock button under 'Authorization' column, user has to click the lock button to allow the post closing step.

Kindly click the 'Lock' button to allow post closing step.

C+831, Post closing, actual costing run, CKMLCP, costing cockpit. , KBA , CO-PC-ACT-2CL , Actual Costing (Public Cloud) , Problem