Issue with uploading images through entity browser in Drupal 8

A little off topic but think this as an alternative:
If the goal is to re-use images in wysiwyg, I would just use IMCE...
If the goal is also to re-use them in an image or file field, you can try the 'file field sources' module.

I'm having exactly the same problem (adding the error as text, and not as an image so that it shows up in the issue search results).

TypeError: Argument 1 passed to file_validate() must implement interface Drupal\file\FileInterface, instance of Drupal\media_entity\Entity\Media given, called in /var/www/mysite/docroot/modules/contrib/entity_browser/src/Plugin/EntityBrowser/WidgetValidation/File.php on line 31 in file_validate() (regel 286 van /var/www/mysite/docroot/core/modules/file/file.module) 
#0 /var/www/mysite/docroot/modules/contrib/entity_browser/src/Plugin/EntityBrowser/WidgetValidation/File.php(31): file_validate(Object(Drupal\media_entity\Entity\Media), Array) 
#1 /var/www/mysite/docroot/modules/contrib/entity_browser/src/WidgetBase.php(319): Drupal\entity_browser\Plugin\EntityBrowser\WidgetValidation\File->validate(Array, Array) 
#2 /var/www/mysite/docroot/modules/contrib/entity_browser/src/WidgetBase.php(294): Drupal\entity_browser\WidgetBase->runWidgetValidators(Array, Array) 
#3 /var/www/mysite/docroot/modules/contrib/dropzonejs/modules/eb_widget/src/Plugin/EntityBrowser/Widget/DropzoneJsEbWidget.php(251): Drupal\entity_browser\WidgetBase->validate(Array, Object(Drupal\Core\Form\FormState)) 
#4 /var/www/mysite/docroot/modules/contrib/entity_browser/src/Form/EntityBrowserForm.php(171): Drupal\dropzonejs_eb_widget\Plugin\EntityBrowser\Widget\DropzoneJsEbWidget->validate(Array, Object(Drupal\Core\Form\FormState)) 
#5 [internal function]: Drupal\entity_browser\Form\EntityBrowserForm->validateForm(Array, Object(Drupal\Core\Form\FormState)) 
#6 /var/www/mysite/docroot/core/lib/Drupal/Core/Form/FormValidator.php(83): call_user_func_array(Array, Array) 
#7 /var/www/mysite/docroot/core/lib/Drupal/Core/Form/FormValidator.php(270): Drupal\Core\Form\FormValidator->executeValidateHandlers(Array, Object(Drupal\Core\Form\FormState)) 
#8 /var/www/mysite/docroot/core/lib/Drupal/Core/Form/FormValidator.php(119): Drupal\Core\Form\FormValidator->doValidateForm(Array, Object(Drupal\Core\Form\FormState), 'entity_browser_...') 
#9 /var/www/mysite/docroot/core/lib/Drupal/Core/Form/FormBuilder.php(571): Drupal\Core\Form\FormValidator->validateForm('entity_browser_...', Array, Object(Drupal\Core\Form\FormState)) 
#10 /var/www/mysite/docroot/core/lib/Drupal/Core/Form/FormBuilder.php(314): Drupal\Core\Form\FormBuilder->processForm('entity_browser_...', Array, Object(Drupal\Core\Form\FormState)) 
#11 /var/www/mysite/docroot/core/lib/Drupal/Core/Controller/FormController.php(74): Drupal\Core\Form\FormBuilder->buildForm('entity_browser_...', Object(Drupal\Core\Form\FormState)) 
#12 [internal function]: Drupal\Core\Controller\FormController->getContentResult(Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\RouteMatch)) 
#13 /var/www/mysite/docroot/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array(Array, Array) 
#14 /var/www/mysite/docroot/core/lib/Drupal/Core/Render/Renderer.php(574): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() 
#15 /var/www/mysite/docroot/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(124): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure)) 
#16 /var/www/mysite/docroot/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) 
#17 [internal function]: Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() 
#18 /var/www/mysite/vendor/symfony/http-kernel/HttpKernel.php(144): call_user_func_array(Object(Closure), Array) 
#19 /var/www/mysite/vendor/symfony/http-kernel/HttpKernel.php(64): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1) 
#20 /var/www/mysite/docroot/core/lib/Drupal/Core/StackMiddleware/Session.php(57): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) 
#21 /var/www/mysite/docroot/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(47): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) 
#22 /var/www/mysite/docroot/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(47): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) 
#23 /var/www/mysite/docroot/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(50): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) 
#24 /var/www/mysite/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) 
#25 /var/www/mysite/docroot/core/lib/Drupal/Core/DrupalKernel.php(656): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) 
#26 /var/www/mysite/docroot/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request)) 
#27 {main}.

Seems to be a duplicate of #2875209: TypeError: Argument 1 passed to file_validate() must implement interface Drupal\file\FileInterface, instance of Drupal\media_entity\Entity\Media given.