Cost distribution of grouping WBS & not allowed due to status

What causes this issue?

The status of grouping WBS element & does not allow cost
distribution.

System Response

All orders and production orders accounted to grouping WBS element
& will be excluded from cost distribution.

How to fix this error?

Check the status of the named grouping WBS element.

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.