Issue #3482321 by globexplorer: Trying to access array offset on value of type...

Issue #3482321 by globexplorer: Trying to access array offset on value of type null in Drupal\group_welcome_message\Form\GroupWelcomeMessageForm->form()

src/Form/GroupWelcomeMessageForm.php

@@ -86,7 +86,7 @@ class GroupWelcomeMessageForm extends EntityForm {
       '#type' => 'textfield',
       '#title' => $settings->get('subject_label'),
       '#maxlength' => 255,
-      '#default_value' => $group_welcome_message->getSubject(),
+      '#default_value' => $group_welcome_message->getSubject() ?? '',
       '#required' => TRUE,
     ];
 
@@ -94,7 +94,7 @@ class GroupWelcomeMessageForm extends EntityForm {
     $form['body'] = [
       '#type' => 'text_format',
       '#title' => $settings->get('body_label'),
-      '#default_value' => $group_welcome_message->getBody()['value'],
+      '#default_value' => $group_welcome_message->getBody()['value'] ?? '',
       '#required' => TRUE,
       '#format' => $settings->get('selected_format'),
       '#allowed_formats' => [
@@ -105,7 +105,7 @@ class GroupWelcomeMessageForm extends EntityForm {
     $form['body_existing'] = [
       '#type' => 'text_format',
       '#title' => $settings->get('body_existing_label'),
-      '#default_value' => $group_welcome_message->getBodyExisting()['value'],
+      '#default_value' => $group_welcome_message->getBodyExisting()['value'] ?? '',
       '#required' => FALSE,
       '#format' => $settings->get('selected_format'),
       '#allowed_formats' => [