Fixed value / lower limit & reoccurs

What causes this issue?

The values and the lower limits of a value range must be unique.
The specified value / the specified lower limit of a range appears 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 the specified value / lower limit of a
range with unique values.

Error message extract from SAP system. Copyright SAP SE.