Steps to reproduce
Create a blog post without image Save or...
Create a blog post including image Save Open up for editing Save it again
Blog post should save the updates Actual result Magento throws an exception "The file was not uploaded." So basically the module always expects a new image to be attached to a post even if there already has been uploaded an image to it.
Exception #0 (Exception): The file was not uploaded. #1 Magento\MediaStorage\Model\File\Uploader->__construct('image', &Magento\MediaStorage\Helper\File\Storage\Database#0000000060cfa2ea000000004348112d#, &Magento\MediaStorage\Helper\File\Storage#0000000060cfa511000000004348112d#, &Magento\MediaStorage\Model\File\Validator\NotProtectedExtension#0000000060cfa510000000004348112d#) called at [vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:111]