The name of the field symbol &1 must start with '<' and end with '>'

What causes this issue?

The name of a field symbol always has to start with '
<' and end with '>'. Other names are not permitted.

System Response

The operation was terminated.

How to fix this error?

Specify a field symbol name that starts with '
<' and ends with '>'.

Procedure for System Administrators

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.