Call to a member function addField() on array

Problem/Motivation

Error when updating the database: "Call to a member function addField() on array"

Steps to reproduce

1. Run composer require 'drupal/carbon_impact_evaluator:^1.2'
2. Run the database update command for your project - drush updb

Proposed resolution

Replace the variable $schema, which is inside the (!$check_field), with another variable so as not to override the other $schema.