& is an area (subscreen). Operation not performed

What causes this issue?

You are editing a subscreen and want to navigate to its definition in
the program.

System Response

The name of a subscreen serves only to identify it in the flow logic.
It does not need to be defined in the program. Therefore, the system
cannot navigate to a definition.

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.