After changing a field's reference method to "Views: Filter by an entity reference view," I am unable access the edit form for the field.
I was working through instructions provided in a stackexchange answer here. In case the link becomes unavailable, here are the steps that produce the error:
1. Edit Entity Reference Field Settings:
Navigate to "Structure" > "Content types."
Choose the content type that contains the entity reference field.
Edit the field settings for your entity reference field.
2. Change "Reference Method":
In the field settings, find the "Reference method" option.
Change it to "Views: Filter by an entity reference view."
3. Configure Entity Reference View:
Create a new entity reference view or select an existing one.
The view should list the nodes you want to appear as options in your exposed filter.
Configure the view to display the fields you want as options in the exposed filter.
4. Configure Exposed Filter in Views:
Create or edit a view that displays the content you want to filter.
In the view, expose the desired entity reference field as a filter.
Under "Filter type to expose," select "Grouped filters."
5. Choose "Grouped Filters":
Choosing "Grouped filters" will provide a better user experience by using a select input with options.
At this point in the instructions, I got stuck, so I could not do step 6 or 7. And then, when I visit the edit form for the entity reference field, I get this error:
The website encountered an unexpected error. Please try again later.
AssertionError: Cannot load the "view" entity with NULL ID. in assert() (line 295 of core\lib\Drupal\Core\Entity\EntityStorageBase.php).
assert(, 'Cannot load the "view" entity with NULL ID.') (Line: 295)
Drupal\Core\Entity\EntityStorageBase->load(NULL) (Line: 122)
Drupal\views\Views::getView(NULL) (Line: 211)
Drupal\views\Plugin\EntityReferenceSelection\ViewsSelection->initializeView(NULL, 'CONTAINS', 0, NULL) (Line: 261)
Drupal\views\Plugin\EntityReferenceSelection\ViewsSelection->getDisplayExecutionResults(NULL, 'CONTAINS', 0) (Line: 234)
Drupal\views\Plugin\EntityReferenceSelection\ViewsSelection->getReferenceableEntities() (Line: 618)
Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem->getSettableOptions(Object) (Line: 138)
Drupal\Core\Field\Plugin\Field\FieldWidget\OptionsWidgetBase->getOptions(Object) (Line: 32)
Drupal\Core\Field\Plugin\Field\FieldWidget\OptionsButtonsWidget->formElement(Object, 0, Array, Array, Object) (Line: 353)
Drupal\Core\Field\WidgetBase->formSingleElement(Object, 0, Array, Array, Object) (Line: 92)
Drupal\Core\Field\WidgetBase->form(Object, Array, Object) (Line: 287)
Drupal\Core\Field\FieldItemList->defaultValuesForm(Array, Object) (Line: 125)
Drupal\field_ui\Form\FieldConfigEditForm->form(Array, Object) (Line: 106)
Drupal\Core\Entity\EntityForm->buildForm(Array, Object)
call_user_func_array(Array, Array) (Line: 536)
Drupal\Core\Form\FormBuilder->retrieveForm('field_config_edit_form', Object) (Line: 283)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 73)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 580)
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: 169)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 81)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
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: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 718)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)
There does not appear to be a good workaround for this problem, aside from rolling back my database. I can't delete the field because that will destroy data.