I have got this error:
The website encountered an unexpected error. Please try again later.
Recoverable fatal error: Object of class Drupal\Core\Url could not be converted to string in Drupal\Component\Render\HtmlEscapedText->__construct() (line 41 of core/lib/Drupal/Component/Render/HtmlEscapedText.php).
Drupal\Component\Render\HtmlEscapedText->__construct(Object) (Line: 204)
Drupal\Core\Utility\Token->replace('[node:field_jissue_cover:entity:url]', Array, Array) (Line: 40)
Drupal\metatag\MetatagToken->replace('[node:field_jissue_cover:entity:url]', Array, Array) (Line: 293)
Drupal\metatag\MetatagManager->generateElements(Array, Object) (Line: 321)
metatag_get_tags_from_route() (Line: 143)
metatag_entity_view_alter(Array, Object, Object) (Line: 501)
Drupal\Core\Extension\ModuleHandler->alter(Array, Array, Object, Object) (Line: 285)
Drupal\Core\Entity\EntityViewBuilder->buildMultiple(Array) (Line: 220)
Drupal\Core\Entity\EntityViewBuilder->build(Array)
call_user_func(Array, Array) (Line: 376)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, ) (Line: 226)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 574)
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) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.view', Object) (Line: 149)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 64)
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: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->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: 656)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)