Fixed values/limits reappear

What causes this issue?

Values and limits of a value range must be unique.
One or more of the specified values / value range limits range appear
more than once.

System Response

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

How to fix this error?

Replace the reoccurrence of these values / value range limits
with unique values.

Error message extract from SAP system. Copyright SAP SE.