Dear Community!

I am moving a working Drupal 8.4 installation from an ubuntu on raspberry to a centOS 7.3 (root server). On the target system there are other running websites, including a working Drupal 8.4

My problem: after migration, including install of composer, setup of MariaDB 10.2, copying of files (rights checked), I can get the static files, like robots.txt, but I get errors with the drupal pages: »The website encountered an unexpected error. Please try again later.«

I cannot use <my.server.tld>/update.php – same error; in /var/log/httpd/error_log I find a lenghty error text – the same text I get when I call <my.server.tld>/core/install.php, this time well formatted on screen.

Could not find any hint in forum helping me further – can you help me?

Thanks in advance,
Michael

text from page (complete):


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Additional uncaught exception thrown while handling exception.

Original

Drupal\Component\Plugin\Exception\PluginException: Plugin (field_group_accordion_item) instance class "Drupal\field_group\Element\AccordionItem" does not exist. in Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass() (line 97 of /var/www/html/freelearners.net/web/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php). 

Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass('field_group_accordion_item', Array, 'Drupal\Core\Render\Element\ElementInterface') (Line: 17)
Drupal\Core\Plugin\Factory\ContainerFactory->createInstance('field_group_accordion_item', Array) (Line: 84)
Drupal\Component\Plugin\PluginManagerBase->createInstance('field_group_accordion_item', Array) (Line: 140)
Drupal\Core\Render\ElementInfoManager->createInstance('field_group_accordion_item') (Line: 110)
Drupal\Core\Render\ElementInfoManager->buildInfo('seven') (Line: 76)
Drupal\Core\Render\ElementInfoManager->getInfo('html') (Line: 298)
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: 576)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 140)
Drupal\Core\Render\Renderer->renderRoot(Array) (Line: 66)
Drupal\Core\Render\BareHtmlPageRenderer->renderBarePage(Array, Object, 'install_page', Array) (Line: 76)
Drupal\Core\ProxyClass\Render\BareHtmlPageRenderer->renderBarePage(Array, Object, 'install_page', Array) (Line: 996)
install_display_output(Array, Array) (Line: 156)
install_drupal(Object) (Line: 44)

Additional

Drupal\Component\Plugin\Exception\PluginException: Plugin (field_group_accordion_item) instance class "Drupal\field_group\Element\AccordionItem" does not exist. in Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass() (line 97 of /var/www/html/freelearners.net/web/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php). 

Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass('field_group_accordion_item', Array, 'Drupal\Core\Render\Element\ElementInterface') (Line: 17)
Drupal\Core\Plugin\Factory\ContainerFactory->createInstance('field_group_accordion_item', Array) (Line: 84)
Drupal\Component\Plugin\PluginManagerBase->createInstance('field_group_accordion_item', Array) (Line: 140)
Drupal\Core\Render\ElementInfoManager->createInstance('field_group_accordion_item') (Line: 110)
Drupal\Core\Render\ElementInfoManager->buildInfo('seven') (Line: 76)
Drupal\Core\Render\ElementInfoManager->getInfo('html') (Line: 298)
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: 576)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 140)
Drupal\Core\Render\Renderer->renderRoot(Array) (Line: 66)
Drupal\Core\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Error', 'install_page', Array) (Line: 76)
Drupal\Core\ProxyClass\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Error', 'install_page', Array) (Line: 996)
install_display_output(Array, Array, Array) (Line: 264)
_drupal_log_error(Array, 1) (Line: 584)
_drupal_exception_handler(Object)

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