Error message

• Warning: foreach() argument must be of type array|object, null given in Drupal\pollions_custom\Form\PrevnextForm->buildForm() (line 59 of modules/custom/pollions_custom/src/Form/PrevnextForm.php).

  Drupal\pollions_custom\Form\PrevnextForm->buildForm(Array, Object)
  call_user_func_array(Array, Array) (Line: 536)
  Drupal\Core\Form\FormBuilder->retrieveForm('prev_next_form', Object) (Line: 284)
  Drupal\Core\Form\FormBuilder->buildForm('Drupal\pollions_custom\Form\PrevnextForm', Object) (Line: 224)
  Drupal\Core\Form\FormBuilder->getForm('Drupal\pollions_custom\Form\PrevnextForm') (Line: 21)
  Drupal\pollions_custom\Plugin\Block\PrevnextBlock->build() (Line: 171)
  Drupal\block\BlockViewBuilder::preRender(Array)
  call_user_func_array('Drupal\block\BlockViewBuilder::preRender', Array) (Line: 113)
  Drupal\Core\Render\Renderer->doTrustedCallback('Drupal\block\BlockViewBuilder::preRender', Array, 'Render #pre_render callbacks must be methods of a class that implements \Drupal\Core\Security\TrustedCallbackInterface or be an anonymous function. The callback was %s. See https://www.drupal.org/node/2966725', 'exception', 'Drupal\Core\Render\Element\RenderCallbackInterface') (Line: 870)
  Drupal\Core\Render\Renderer->doCallback('#pre_render', 'Drupal\block\BlockViewBuilder::preRender', Array) (Line: 432)
  Drupal\Core\Render\Renderer->doRender(Array) (Line: 504)
  Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 248)
  Drupal\Core\Render\Renderer->render(Array) (Line: 475)
  Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 191)
  __TwigTemplate_b131b2fc6584c37017e9401591d3f4af->doDisplay(Array, Array) (Line: 360)
  Twig\Template->yield(Array) (Line: 335)
  Twig\Template->render(Array) (Line: 38)
  Twig\TemplateWrapper->render(Array) (Line: 33)
  twig_render_template('themes/custom/pollions/templates/layout/page--poll--%.html.twig', Array) (Line: 348)
  Drupal\Core\Theme\ThemeManager->render('page', Array) (Line: 491)
  Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 248)
  Drupal\Core\Render\Renderer->render(Array) (Line: 475)
  Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 109)
  __TwigTemplate_1eb2c6fb2486ac6490bc3a21319b8fb5->doDisplay(Array, Array) (Line: 360)
  Twig\Template->yield(Array) (Line: 335)
  Twig\Template->render(Array) (Line: 38)
  Twig\TemplateWrapper->render(Array) (Line: 33)
  twig_render_template('themes/custom/pollions/templates/layout/html.html.twig', Array) (Line: 348)
  Drupal\Core\Theme\ThemeManager->render('html', Array) (Line: 491)
  Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 248)
  Drupal\Core\Render\Renderer->render(Array) (Line: 158)
  Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 638)
  Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 153)
  Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
  Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object)
  call_user_func(Array, Object, 'kernel.view', Object) (Line: 111)
  Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.view') (Line: 186)
  Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
  Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 53)
  Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
  Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
  Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
  Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 48)
  Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
  Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
  Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
  Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 741)
  Drupal\Core\DrupalKernel->handle(Object) (Line: 19)
  

• Warning: Trying to access array offset on value of type bool in pollions_custom_form_alter() (line 187 of modules/custom/pollions_custom/pollions_custom.module).

  pollions_custom_form_alter(Array, Object, 'poll_view_form_171') (Line: 553)
  Drupal\Core\Extension\ModuleHandler->alter('form', Array, Object, 'poll_view_form_171') (Line: 834)
  Drupal\Core\Form\FormBuilder->prepareForm('poll_view_form_171', Array, Object) (Line: 285)
  Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 224)
  Drupal\Core\Form\FormBuilder->getForm(Object, Object, 'full') (Line: 61)
  Drupal\poll\PollPostRenderCache->renderViewForm('171', 'full', 'en')
  call_user_func_array(Array, Array) (Line: 113)
  Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #lazy_builder callbacks must be methods of a class that implements \Drupal\Core\Security\TrustedCallbackInterface or be an anonymous function. The callback was %s. See https://www.drupal.org/node/2966725', 'exception', 'Drupal\Core\Render\Element\RenderCallbackInterface') (Line: 870)
  Drupal\Core\Render\Renderer->doCallback('#lazy_builder', 'poll.post_render_cache:renderViewForm', Array) (Line: 411)
  Drupal\Core\Render\Renderer->doRender(Array, 1) (Line: 248)
  Drupal\Core\Render\Renderer->render(Array, 1) (Line: 165)
  Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}() (Line: 638)
  Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 164)
  Drupal\Core\Render\Renderer->renderInIsolation(Array) (Line: 191)
  Drupal\Core\Render\Renderer->doRenderPlaceholder(Array) (Line: 723)
  Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}()
  Fiber->start() (Line: 731)
  Drupal\Core\Render\Renderer->replacePlaceholders(Array) (Line: 608)
  Drupal\Core\Render\Renderer->doRender(Array, 1) (Line: 248)
  Drupal\Core\Render\Renderer->render(Array, 1) (Line: 153)
  Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}() (Line: 638)
  Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 152)
  Drupal\Core\Render\Renderer->renderRoot(Array) (Line: 288)
  Drupal\Core\Render\HtmlResponseAttachmentsProcessor->renderPlaceholders(Object) (Line: 74)
  Drupal\big_pipe\Render\BigPipeResponseAttachmentsProcessor->processAttachments(Object) (Line: 45)
  Drupal\Core\EventSubscriber\HtmlResponseSubscriber->onRespond(Object, 'kernel.response', Object)
  call_user_func(Array, Object, 'kernel.response', Object) (Line: 111)
  Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.response') (Line: 214)
  Symfony\Component\HttpKernel\HttpKernel->filterResponse(Object, Object, 1) (Line: 202)
  Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
  Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 53)
  Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
  Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
  Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
  Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 48)
  Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
  Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
  Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
  Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 741)
  Drupal\Core\DrupalKernel->handle(Object) (Line: 19)