Segment & cannot be deleted from this view

What causes this issue?

Deleting segment &v1& from the view leads to a syntax error in the IDoc
type. This segment must be present in the view.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.