I'm using Drupal core 8.6 with Focal Point development version: 8.x-1.x-dev (updated 10 Jan 2020 ).
After editing an image with Image (focal point) set as the widget on the media type edit form (admin/structure/media/manage/image/form-display), I get the following error message:
The website encountered an unexpected error. Please try again later.
Error: Call to a member function isNew() on null in focal_point_entity_update() (line 73 of modules\contrib\focal_point\focal_point.module).
focal_point_entity_update(Object)
call_user_func_array('focal_point_entity_update', Array) (Line: 403)
Drupal\Core\Extension\ModuleHandler->invokeAll('entity_update', Array) (Line: 206)
Drupal\Core\Entity\EntityStorageBase->invokeHook('update', Object) (Line: 756)
Drupal\Core\Entity\ContentEntityStorageBase->invokeHook('update', Object) (Line: 507)
Drupal\Core\Entity\EntityStorageBase->doPostSave(Object, 1) (Line: 641)
Drupal\Core\Entity\ContentEntityStorageBase->doPostSave(Object, 1) (Line: 432)
Drupal\Core\Entity\EntityStorageBase->save(Object) (Line: 774)
Drupal\Core\Entity\Sql\SqlContentEntityStorage->save(Object) (Line: 29)
Drupal\media\MediaStorage->save(Object) (Line: 390)
Drupal\Core\Entity\Entity->save() (Line: 296)
Drupal\Core\Entity\EntityForm->save(Array, Object) (Line: 61)
Drupal\media\MediaForm->save(Array, Object)
call_user_func_array(Array, Array) (Line: 111)
Drupal\Core\Form\FormSubmitter->executeSubmitHandlers(Array, Object) (Line: 51)
Drupal\Core\Form\FormSubmitter->doSubmitForm(Array, Object) (Line: 589)
Drupal\Core\Form\FormBuilder->processForm('media_image_edit_form', Array, Object) (Line: 318)
Drupal\Core\Form\FormBuilder->buildForm('media_image_edit_form', Object) (Line: 93)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 582)
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: 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: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 669)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)
This seems to happen only when editing an image. I can create an image and set the focal point with no problem. However, when I try to edit the image, the above error happens. So, basically, I can create an image entity and use the Image (Focal Point) widget but, I can't subsequently edit and save that image.