The transaction is obsolete (see SAP Note 441872)

What causes this issue?

You want to manually post actual data.

System Response

The transaction is obsolete and no longer supported.

How to fix this error?

Use the new transactions for manual actual postings when you want to
enter data online or the corresponding BAPIs for mass data processing.
The following BAPIs are available:
Cost reposting:
BAPI_ACC_PRIMARY_COSTS_CHECK
BAPI_ACC_PRIMARY_COSTS_POST
Revenue reposting
BAPI_ACC_REVENUES_CHECK
BAPI_ACC_REVENUES_POST
Activity allocation
BAPI_ACC_ACTIVITY_ALLOC_CHECK
BAPI_ACC_ACTIVITY_ALLOC_POST
Entry of statistical key figures
BAPI_ACC_STAT_KEY_FIG_CHECK
BAPI_ACC_STAT_KEY_FIG_POST
Manual cost allocation
BAPI_ACC_MANUAL_ALLOC_CHECK
BAPI_ACC_MANUAL_ALLOC_POST
Entry of sender activity
BAPI_ACC_SENDER_ACTIVITY_CHECK
BAPI_ACC_SENDER_ACTIVITY_POST
Reversal of a manual actual posting
BAPI_ACC_ACT_POSTINGS_REVERSE

Error message extract from SAP system. Copyright SAP SE.