Segment definition was not saved, since unchanged or initial

What causes this issue?

The current segment definition was not changed. It has
the same state as the predecessor or
the version last saved or
a segment definition which is to be created still has no fields.
It is therefore not necessary to save it.

System Response

It was not saved.

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.