Cannot cancel cost distribution for grouping WBS element &1

What causes this issue?

Problems occured when cancelling the cost distribution for grouping WBS
element &V1&:
The selected period does not match the period for the last cost
distribution: &V2& / &V3&.
Pegging has been carried out since the last cost distribution.

System Response

Grouping WBS element &V1& is excluded from processing.

How to fix this error?

Check your entries.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.