<!-- Please search existing work items before filing to avoid duplicates. --> ## Summary In this issue https://git.drupalcode.org/project/ai/-/work_items/3549657 prompt entities were introduced to CKEditor plugins. Unfortunately, when one tries to create a new prompt, there is a fatal error: ``` TypeError: Drupal\Core\Render\MainContent\AjaxRenderer::renderResponse(): Argument #1 ($main_content) must be of type array, null given, called in /var/www/html/web/core/lib/Drupal/Core/Form/FormAjaxResponseBuilder.php on line 102 in Drupal\Core\Render\MainContent\AjaxRenderer->renderResponse() (line 48 of /var/www/html/web/core/lib/Drupal/Core/Render/MainContent/AjaxRenderer.php) #0 /var/www/html/web/core/lib/Drupal/Core/Form/FormAjaxResponseBuilder.php(102): Drupal\Core\Render\MainContent\AjaxRenderer->renderResponse() #1 /var/www/html/web/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php(112): Drupal\Core\Form\FormAjaxResponseBuilder->buildResponse() #2 /var/www/html/vendor/symfony/event-dispatcher/EventDispatcher.php(246): Drupal\Core\Form\EventSubscriber\FormAjaxSubscriber->onException() #3 /var/www/html/vendor/symfony/event-dispatcher/EventDispatcher.php(206): Symfony\Component\EventDispatcher\EventDispatcher::Symfony\Component\EventDispatcher\{closure}() #4 /var/www/html/vendor/symfony/event-dispatcher/EventDispatcher.php(56): Symfony\Component\EventDispatcher\EventDispatcher->callListeners() #5 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(241): Symfony\Component\EventDispatcher\EventDispatcher->dispatch() #6 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(91): Symfony\Component\HttpKernel\HttpKernel->handleThrowable() #7 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/Session.php(53): Symfony\Component\HttpKernel\HttpKernel->handle() #8 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle() #9 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/ContentLength.php(28): Drupal\Core\StackMiddleware\KernelPreHandle->handle() #10 /var/www/html/web/core/modules/big_pipe/src/StackMiddleware/ContentLength.php(32): Drupal\Core\StackMiddleware\ContentLength->handle() #11 /var/www/html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(118): Drupal\big_pipe\StackMiddleware\ContentLength->handle() #12 /var/www/html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(92): Drupal\page_cache\StackMiddleware\PageCache->pass() #13 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle() #14 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() #15 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/AjaxPageState.php(53): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() #16 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(54): Drupal\Core\StackMiddleware\AjaxPageState->handle() #17 /var/www/html/web/core/lib/Drupal/Core/DrupalKernel.php(745): Drupal\Core\StackMiddleware\StackedHttpKernel->handle() #18 /var/www/html/web/index.php(19): Drupal\Core\DrupalKernel->handle() #19 {main} ``` ## Steps to reproduce 1. Enable AI CKEditor module (dblog optionally to see the error in UI). 2. Go to configure the text format here `/admin/config/content/formats` 3. Choose one and add "AI Assitant" button to a toolbar. 4. Observe right away that plugins settings do not appear. 5. Try to save anyway and go back to edit. 6. Observe there are plugin settings. 7. Now go to "Summarize" settings and click on "Create new prompt" button. 8. See that ajax spinner appeared and disappeared - nothing visually happened. 9. Check "Recent logged messages" and see the error described above. ## Expected result It is possible to create a new prompt like anywhere else, for example in AI Content Suggestion settings ## Actual result No prompt can be created ## Environment - Drupal version: 11.3.11 - Module version: 1.5.x - PHP version: 8.3 - Provider: N/A - Last known working version: N/A