If you get error :

Notice: Undefined property: CustompropertiesViewShow::$result_summary in ...components\com_customproperties\views\show\tmpl\default.php on line 18

you just hit a bug - a small one, but yet a bug.

Most servers are set not to show 'Notice' type errors, that's why few people reported this issue.

It has been fixed with version 1.98.1 of component.