The master record for allocation cost element & was not found

What causes this issue?

The allocation cost element &V1& has been entered in the activity type
&V2&.
However, a valid master record for this allocation cost element was not
found for the last day of the planning period.

System Response

Processing was cancelled.

How to fix this error?

Correct the inconsistency by
recreating the allocation cost element &V1&, or
<DS:TRAN.KA06>Execute function</>
entering a different allocation cost type in the master record of
allocation element &V2&
<DS:TRAN.KA06>Execute function</>.

Error message extract from SAP system. Copyright SAP SE.