Crash on empty section

Problem/Motivation

Module crashes if section FALSE

Steps to reproduce

I inherited a dog's breakfast of layout builder website, it has sections which are FALSE!!!
This module should not crash and report those sections as missing config.

Proposed resolution

check if $unserialized_data is an object (or set to FALSE) and display if it's missing

Remaining tasks

update code

User interface changes

adds indication if section data/config is missing

API changes

none

Data model changes

none