"Undefined" error when loading profiles in detail view

[pjmonks]

Description

A console error appears when viewing the details of a catalogue item related to profile views:

ERROR SyntaxError: "undefined" is not valid JSON
    at JSON.parse (<anonymous>)
    at ProfileDataViewComponent.loadDefaultCustomProfile (profile-data-view.component.ts:864:12)
    at profile-data-view.component.ts:218:14
    at Object.next (Subscriber.js:110:13)
    at SafeSubscriber._next (Subscriber.js:60:26)
    at SafeSubscriber.next (Subscriber.js:31:18)
    at OperatorSubscriber._next (Subscriber.js:60:26)
    at OperatorSubscriber.next (Subscriber.js:31:18)
    at OperatorSubscriber._next (Subscriber.js:60:26)
    at OperatorSubscriber.next (Subscriber.js:31:18)

Steps to reproduce

1. Select any tree node in the model tree to view their details
2. Inspect the browser console to see the error logged

Expected behavior

Handle this situation gracefully