Manual depreciation not allowed with depreciation key &

INCLUDE 'AA_AFA_ERROR' OBJECT DOKU ID TX LANGUAGE E

What causes this issue?

It is not possible to have manual depreciation in combination with a
depreciation key, which is used to forecast depreciation.

System Response

The document with manual depreciation cannot be posted.

How to fix this error?

Choose a depreciation key which does not automatically
forecast depreciation.

Error message extract from SAP system. Copyright SAP SE.