Only Reporting hierarchies can be processed here

What causes this issue?

You want to change a hierarchy variant that is assigned to an FM area
and fiscal year as an operative hierarchy variant (that is, it can be
budgeted for and posted to).

System Response

Changes are not permitted

How to fix this error?

Choose a hierarchy variant that is only used in Reporting.

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.