Class 'Drupal\select2\Plugin\Field\FieldWidget\Select2EntityReferenceWidget' not found

Problem/Motivation

After enabling the DEV version of this module, the form display page of all content types throw the following error, this did not happen with the beta1 version.

The website encountered an unexpected error. Please try again later.
Error: Class 'Drupal\select2\Plugin\Field\FieldWidget\Select2EntityReferenceWidget' not found in require() (line 23 of modules/contrib/entity_reference_views/src/Plugin/Field/FieldWidget/Select2ViewsWidget.php).
require() (Line: 112)
Symfony\Component\ClassLoader\ApcClassLoader->loadClass('Drupal\entity_reference_views\Plugin\Field\FieldWidget\Select2ViewsWidget')
spl_autoload_call('Drupal\entity_reference_views\Plugin\Field\FieldWidget\Select2ViewsWidget')
class_exists('Drupal\entity_reference_views\Plugin\Field\FieldWidget\Select2ViewsWidget') (Line: 96)
Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass('entity_reference_views_select2', Array) (Line: 800)
Drupal\field_ui\Form\EntityDisplayFormBase->getApplicablePluginOptions(Object) (Line: 310)
Drupal\field_ui\Form\EntityDisplayFormBase->buildFieldRow(Object, Array, Object) (Line: 40)
Drupal\field_ui\Form\EntityFormDisplayEditForm->buildFieldRow(Object, Array, Object) (Line: 218)
Drupal\field_ui\Form\EntityDisplayFormBase->form(Array, Object) (Line: 149)
Drupal\Core\Entity\EntityForm->buildForm(Array, Object)
call_user_func_array(Array, Array) (Line: 532)
Drupal\Core\Form\FormBuilder->retrieveForm('entity_form_display_edit_form', Object) (Line: 278)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 91)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 573)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 151)
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: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
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: 708)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Steps to reproduce

- Enable the DEV version of the module.
- Create a content type.
- Browse to the content type's form display page.