There is already a hierarchy level with this description

What causes this issue?

You are not permitted to change an existing hierarchy level so that it
has the same description as another hierarchy level.

System Response

The change you have made has been ignored.

How to fix this error?

If you wish to insert this hierarchy level below several other
hierarchy levels, you must create this hierarchy level again. When the
names are the same, a reference is produced automatically.

Error message extract from SAP system. Copyright SAP SE.