Name & has already been assigned to a template or field text

What causes this issue?

You are editing a graphical element (pushbutton, box, checkbox, radio
button) and want to assign a name to it.
However, this new field name already belongs to an input/output field
or to a field text.

System Response

The system identifies screen elements by their names. Fields of the
same name belong together. Only the following element pairs can have
the same name:

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

an input/output field and a field text
a checkbox and its field text
a radio button and its field text
The system rejects the new name.

How to fix this error?

Use a unique name.

Error message extract from SAP system. Copyright SAP SE.