FormState getValue on checkbox elements in hierarchical / tabular form structures broken?
Anyone still having this problem please allow collections of form elements using #tree set to TRUE. Its applied to the &quot;parent&quot; element, as the #tree property cascades to sub-elements. Use where you previously used in form calls. See D7 #tree and #parents on drupal.org.
Solution
Example for above case, change $form['#tree'] = TRUE; to $form['access']['#tree'] = TRUE; then the value will be obtained using $checked = $form_state-&gt;getValue(['access', 0, 'view']);.