Error message

Notice: Undefined index: #items in _set_upcoming_sessions_data() (line 170 of modules/custom/class/class.module). _set_upcoming_sessions_data(Object, Array) (Line: 40) class_preprocess_node(Array, 'node', Array) (Line: 287) Drupal\Core\Theme\ThemeManager->render('node', Array) (Line: 431) Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 200) Drupal\Core\Render\Renderer->render(Array, ) (Line: 226) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 573) Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 227) Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 117) 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('kernel.view', Object) (Line: 156) Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68) Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57) Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47) Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 191) Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 128) Drupal\page_cache\StackMiddleware\PageCache->lookup(Object, 1, 1) (Line: 82) Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23) Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 694) Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Warning: Invalid argument supplied for foreach() in _set_upcoming_sessions_data() (line 170 of modules/custom/class/class.module). _set_upcoming_sessions_data(Object, Array) (Line: 40) class_preprocess_node(Array, 'node', Array) (Line: 287) Drupal\Core\Theme\ThemeManager->render('node', Array) (Line: 431) Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 200) Drupal\Core\Render\Renderer->render(Array, ) (Line: 226) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 573) Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 227) Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 117) 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('kernel.view', Object) (Line: 156) Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68) Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57) Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47) Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 191) Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 128) Drupal\page_cache\StackMiddleware\PageCache->lookup(Object, 1, 1) (Line: 82) Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23) Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 694) Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Notice: Undefined index: #items in _set_upcoming_sessions_data() (line 191 of modules/custom/class/class.module). _set_upcoming_sessions_data(Object, Array) (Line: 40) class_preprocess_node(Array, 'node', Array) (Line: 287) Drupal\Core\Theme\ThemeManager->render('node', Array) (Line: 431) Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 200) Drupal\Core\Render\Renderer->render(Array, ) (Line: 226) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 573) Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 227) Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 117) 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('kernel.view', Object) (Line: 156) Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68) Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57) Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47) Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 191) Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 128) Drupal\page_cache\StackMiddleware\PageCache->lookup(Object, 1, 1) (Line: 82) Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23) Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 694) Drupal\Core\DrupalKernel->handle(Object) (Line: 19)