Fatal error after upgrade to beta-2

I am seeing a fatal error after upgrading to 1.0-beta2 on a page that just displays a custom entity (i.e. not a search page).
It has a block that displays links to switch the displayed entity language.

I get the following error:

The website encountered an unexpected error. Please try again later.
Error: Call to a member function getId() on null in facets_language_switch_links_alter() (line 374 of modules/contrib/facets/facets.module).

facets_language_switch_links_alter(Array, 'language_content', Object) (Line: 501)
Drupal\Core\Extension\ModuleHandler->alter('language_switch_links', Array, 'language_content', Object) (Line: 417)
Drupal\language\ConfigurableLanguageManager->getLanguageSwitchLinks('language_content', Object) (Line: 90)
Drupal\language\Plugin\Block\LanguageBlock->build() (Line: 90)
Drupal\as_language\Plugin\Block\ASTranslationLanguageBlock->build() (Line: 203)
Drupal\block\BlockViewBuilder::preRender(Array)
call_user_func('Drupal\block\BlockViewBuilder::preRender', Array) (Line: 378)
Drupal\Core\Render\Renderer->doRender(Array, 1) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, 1) (Line: 151)
Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}() (Line: 588)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 152)
Drupal\Core\Render\Renderer->renderPlain(Array) (Line: 166)
Drupal\Core\Render\Renderer->renderPlaceholder('', Array) (Line: 673)
Drupal\Core\Render\Renderer->replacePlaceholders(Array) (Line: 558)
Drupal\Core\Render\Renderer->doRender(Array, 1) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, 1) (Line: 139)
Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}() (Line: 588)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 140)
Drupal\Core\Render\Renderer->renderRoot(Array) (Line: 258)
Drupal\Core\Render\HtmlResponseAttachmentsProcessor->renderPlaceholders(Object) (Line: 131)
Drupal\Core\Render\HtmlResponseAttachmentsProcessor->processAttachments(Object) (Line: 78)
Drupal\as_base\Render\ASMetadataResponseAttachmentsProcessor->processAttachments(Object) (Line: 70)
Drupal\as_rule_engine\Render\InlineContentBoxDetailsStateAttachmentsProcessor->processAttachments(Object) (Line: 45)
Drupal\Core\EventSubscriber\HtmlResponseSubscriber->onRespond(Object, 'kernel.response', Object) (Line: 108)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.response', Object) (Line: 193)
Symfony\Component\HttpKernel\HttpKernel->filterResponse(Object, Object, 1) (Line: 175)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 30)
Drupal\prefetch_cache\StackMiddleware\PrefetchCacheAfterSessionInitialized->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: 41)
Drupal\as_segment\StackMiddleware\ASSegmentMiddleware->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 59)
Drupal\prefetch_cache\StackMiddleware\PrefetchCacheBeforePageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 658)
Drupal\Core\DrupalKernel->handle(Object) (Line: 30)

It seems the link arrays being processed do not necessarily have a language object under the key 'language'.