Warning: Undefined array key "" in Drupal\better_exposed_filters\BetterExposedFiltersHelper::sortNestedOptions() (line 202 of modules/contrib/better_exposed_filters/src/BetterExposedFiltersHelper.php).
Drupal\better_exposed_filters\BetterExposedFiltersHelper::sortNestedOptions(Array, '-') (Line: 352)
Drupal\better_exposed_filters\Plugin\better_exposed_filters\filter\FilterWidgetBase->processSortedOptions(Array, Object, Array)
call_user_func_array(Array, Array) (Line: 1006)
Drupal\Core\Form\FormBuilder->doBuildForm('views_exposed_form', Array, Object) (Line: 1069)
Drupal\Core\Form\FormBuilder->doBuildForm('views_exposed_form', Array, Object) (Line: 579)
Drupal\Core\Form\FormBuilder->processForm('views_exposed_form', Array, Object) (Line: 326)
Drupal\Core\Form\FormBuilder->buildForm('\Drupal\views\Form\ViewsExposedForm', Object) (Line: 134)
Drupal\views\Plugin\views\exposed_form\ExposedFormPluginBase->renderExposedForm() (Line: 1297)
Drupal\views\ViewExecutable->build() (Line: 393)
Drupal\views\Plugin\views\display\PathPluginBase->execute() (Line: 198)
Drupal\views\Plugin\views\display\Page->execute() (Line: 1689)
Drupal\views\ViewExecutable->executeDisplay('page', Array) (Line: 81)
Drupal\views\Element\View::preRenderViewElement(Array)
call_user_func_array(Array, Array) (Line: 113)
Drupal\Core\Render\Renderer->doTrustedCallback(Array, 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', Array, Array) (Line: 432)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 248)
Drupal\Core\Render\Renderer->render(Array, ) (Line: 238)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 638)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 239)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 128)
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: 50)
Drupal\ban\BanMiddleware->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)