Hello,
I find multiple PHP notices in the logs when visiting website pages.
Maybe it's only specific on my Drupal.
I don't have the time now, i will try to find out later eventually.
Here is the logged notice :
Notice : Undefined variable: class_ dans Drupal\display_fields\Plugin\DisplayFieldsField\FieldExtraField->getFieldBuild() (/var/www/html/web/modules/contrib/display_fields/src/Plugin/DisplayFieldsField/FieldExtraField.php ligne 400)
#0 /var/www/html/web/core/includes/bootstrap.inc(347): _drupal_error_handler_real(8, 'Undefined varia...', '/var/www/html/w...', 400)
#1 /var/www/html/web/modules/contrib/display_fields/src/Plugin/DisplayFieldsField/FieldExtraField.php(400): _drupal_error_handler(8, 'Undefined varia...', '/var/www/html/w...', 400, Array)
#2 /var/www/html/web/modules/contrib/display_fields/display_fields.module(45): Drupal\display_fields\Plugin\DisplayFieldsField\FieldExtraField->getFieldBuild(Array, Array, Array, Object(Drupal\block_content\Entity\BlockContent), 'default', 'fr')
#3 /var/www/html/web/core/lib/Drupal/Core/Extension/ModuleHandler.php(562): display_fields_entity_view_alter(Array, Object(Drupal\block_content\Entity\BlockContent), Object(Drupal\Core\Entity\Entity\EntityViewDisplay))
#4 /var/www/html/web/core/lib/Drupal/Core/Entity/EntityViewBuilder.php(305): Drupal\Core\Extension\ModuleHandler->alter('block_content_v...', Array, Object(Drupal\block_content\Entity\BlockContent), Object(Drupal\Core\Entity\Entity\EntityViewDisplay))
#5 /var/www/html/web/core/modules/block_content/src/BlockContentViewBuilder.php(36): Drupal\Core\Entity\EntityViewBuilder->buildMultiple(Array)
#6 /var/www/html/web/core/modules/block_content/src/BlockContentViewBuilder.php(24): Drupal\block_content\BlockContentViewBuilder->viewMultiple(Array, 'full', NULL)
#7 /var/www/html/web/core/modules/block_content/src/Plugin/Block/BlockContentBlock.php(187): Drupal\block_content\BlockContentViewBuilder->view(Object(Drupal\block_content\Entity\BlockContent), 'full')
#8 /var/www/html/web/core/modules/block/src/BlockViewBuilder.php(171): Drupal\block_content\Plugin\Block\BlockContentBlock->build()
#9 [internal function]: Drupal\block\BlockViewBuilder::preRender(Array)
#10 /var/www/html/web/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php(101): call_user_func_array(Array, Array)
#11 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(772): Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_ren...', 'exception', 'Drupal\\Core\\Ren...')
#12 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(363): Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array)
#13 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(435): Drupal\Core\Render\Renderer->doRender(Array)
#14 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(201): Drupal\Core\Render\Renderer->doRender(Array, false)
#15 /var/www/html/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#16 /var/www/html/web/sites/default/files/php/twig/63cba5476d825_page.html.twig_TFTExDFUqXYK82tgEOmWG63aE/FuysxKUpMxlTm8lkKjuWvm3jX3LauxHp19ZaJFrDtKw.php(89): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#17 /var/www/html/vendor/twig/twig/src/Template.php(405): __TwigTemplate_b3187a4a2de2e40279e126d16bb316b619f60aff8b316a8741efcc60ce49de62->doDisplay(Array, Array)
#18 /var/www/html/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#19 /var/www/html/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#20 /var/www/html/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#21 /var/www/html/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('themes/custom/g...', Array)
#22 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(422): Drupal\Core\Theme\ThemeManager->render('page', Array)
#23 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(201): Drupal\Core\Render\Renderer->doRender(Array, false)
#24 /var/www/html/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#25 /var/www/html/web/sites/default/files/php/twig/63cba5476d825_html.html.twig_FMIDRWgYIIwo1R5WtNbgJAvDc/ewmeVY4yPCCFz_Fr5tii1Mj-kpsCM_LWZDuGximKN4M.php(95): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#26 /var/www/html/vendor/twig/twig/src/Template.php(405): __TwigTemplate_2d78ece075f3fd2ea785a9db87d51f654f1363b09f1d73e9c39fde2fa4e4b401->doDisplay(Array, Array)
#27 /var/www/html/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#28 /var/www/html/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#29 /var/www/html/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#30 /var/www/html/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('themes/custom/g...', Array)
#31 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(422): Drupal\Core\Theme\ThemeManager->render('html', Array)
#32 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(201): Drupal\Core\Render\Renderer->doRender(Array, false)
#33 /var/www/html/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(162): Drupal\Core\Render\Renderer->render(Array)
#34 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(564): Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}()
#35 /var/www/html/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(163): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#36 /var/www/html/web/core/lib/Drupal/Core/EventSubscriber/MainContentViewSubscriber.php(90): Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#37 [internal function]: Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#38 /var/www/html/web/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(142): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#39 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(174): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view')
#40 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(81): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#41 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#42 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#43 /var/www/html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(191): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#44 /var/www/html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(128): Drupal\page_cache\StackMiddleware\PageCache->fetch(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#45 /var/www/html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(82): Drupal\page_cache\StackMiddleware\PageCache->lookup(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#46 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#47 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#48 /var/www/html/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#49 /var/www/html/web/core/lib/Drupal/Core/DrupalKernel.php(709): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#50 /var/www/html/web/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#51 {main}