Web Services; When "Make Web Services unavailable" is checked, the error notification "widget_ui.LoadStyle:Failed to retrieve Style information" appears

When Web Services are configured to be "unavailable", only a certain sub-set of functionality is available, even to the Web Services administration facility.

This resulted in the error notification "widget_ui.LoadStyle:Failed to retrieve Style information" appearing several times.

This notification is no longer displayed in the Web Administration facility.

NOTE: An HTTP error 503 is still generated and a warning given in the web browser's developer console instead.