Empty tables even when it has related records

Problem/Motivation

Some pages start to showing an empty tables, even when the pagination was showing several pages. Also, some of these pages actually had data, which makes us wonder why other pages were empty. That's when we understood that some of the related entity type didn't have the same structure as we see on nodes and taxonomies for example.

In this case, the problem was caused by Contact Form messages. It had an entity reference field, but it was failing to load it on usage report, resulting in a empty line instead.

Steps to reproduce

Place an entity reference field in a Contact Form. In order to be simpler, configure this entity reference field to accept only Article nodes.

Create now article node. We will use it in the contact message form.

No, go to a page where you see this Contact Form, choose the article you just created in the field you have added, and submit the form in order to save it.

Open the article you have created, and switch to the Usage tab.

You won't the Contact Form message there.

Proposed resolution

The error is caused because on code it expects the attribute type, while checking the relate entity. This attribute doesn't exists for all entity types, so it must be replaced by something that better fits the condition.