& characteristics were not transferred

What causes this issue?

You have attempted to insert a characteristic under a node that already
exists there.
A characteristic is only allowed to appear once directly under a node.
An overlap with intervals is also not allowed here.

System Response

The double characteristics were not transferred into the hierarchy.

How to fix this error?

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.