Select existing tab, throws a warning

So when I go the "Existing tab", I get the following warning:

Warning: Invalid argument supplied for foreach() in Drupal\media_fotoweb\Plugin\EntityBrowser\Widget\FotowebSelection->prepareEntities() (line 210 of modules/contrib/media_fotoweb/src/Plugin/EntityBrowser/Widget/FotowebSelection.php).
Drupal\media_fotoweb\Plugin\EntityBrowser\Widget\FotowebSelection->prepareEntities(Array, Object) (Line: 292)
Drupal\entity_browser\WidgetBase->validate(Array, Object) (Line: 220)
Drupal\entity_browser\Form\EntityBrowserForm->validateForm(Array, Object)
call_user_func_array(Array, Array) (Line: 82)
Drupal\Core\Form\FormValidator->executeValidateHandlers(Array, Object) (Line: 275)
Drupal\Core\Form\FormValidator->doValidateForm(Array, Object, 'entity_browser_image_browser_form') (Line: 118)
Drupal\Core\Form\FormValidator->validateForm('entity_browser_image_browser_form', Array, Object) (Line: 69)
Drupal\autosave_form\Form\AutosaveFormValidator->validateForm('entity_browser_image_browser_form', Array, Object) (Line: 576)
Drupal\Core\Form\FormBuilder->processForm('entity_browser_image_browser_form', Array, Object) (Line: 144)
Drupal\autosave_form\Form\AutosaveFormBuilder->processForm('entity_browser_image_browser_form', Array, Object) (Line: 319)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 97)
Drupal\autosave_form\Form\AutosaveFormBuilder->buildForm(Object, 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: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 49)
Asm89\Stack\Cors->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: 693)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

it seems there's a problem with "autosave_form" module