I'm trying to use the paging capability by "Change the display plugin on 'Manage Display'->'Format'" as described at https://www.drupal.org/project/field_pager →
Install the Field Pager module into Drupal 10.0.8, then go to Manage, Structure, Content Types. Edit a Content Type and then click the Manage Display tab.
With verbose logging the error reads :
The website encountered an unexpected error. Please try again later.
Drupal\Component\Plugin\Exception\PluginException: Plugin (image_pager) instance class "Drupal\field_pager\Plugin\Field\FieldFormatter\FieldImagePager" does not exist. in Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass() (line 97 of core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php).
Drupal\field_ui\Form\EntityDisplayFormBase->getApplicablePluginOptions() (Line: 301)
Drupal\field_ui\Form\EntityDisplayFormBase->buildFieldRow() (Line: 40)
Drupal\field_ui\Form\EntityViewDisplayEditForm->buildFieldRow() (Line: 209)
Drupal\field_ui\Form\EntityDisplayFormBase->form() (Line: 106)
Drupal\Core\Entity\EntityForm->buildForm()
call_user_func_array() (Line: 534)
Drupal\Core\Form\FormBuilder->retrieveForm() (Line: 281)
Drupal\Core\Form\FormBuilder->buildForm() (Line: 73)
Drupal\Core\Controller\FormController->getContentResult()
call_user_func_array() (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 580)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 163)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 74)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 58)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 686)
Drupal\Core\DrupalKernel->handle() (Line: 19)
Active
2.0
Code
Edit the file FieldImagePager.php in the src/Plugin/Field/FieldFormatter directory.
On line 3, change namespace Drupal\image\Plugin\Field\FieldFormatter; to namespace Drupal\field_pager\Plugin\Field\FieldFormatter;.
And, add this line: use Drupal\image\Plugin\Field\FieldFormatter\ImageFormatter; in the top part with the other use statements.
Patch or merge request on request.