The general ledger was not selected

What causes this issue?

Although this is an activity that must post to the account balances,
this ledger (account balances) has not been selected.

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?

Please check the assignment of the activities to the ledgers.
<DS:TRAN.GCL2>Check assignments</>

Error message extract from SAP system. Copyright SAP SE.