We can drag files in to AEM, but when we quick publish or manage publication and publish the files do not go live. Also, image files are not showing previews either. The system is saying that the files have been successfully published, but the address is showing a 404 error.
When author instance shows successfully published but when same asset shows 404 when its accessed via dispatcher/publisher then please check replication agent queue to make sure asset is successfully pushed to publish instance or not? there are chances that asset still in replication queue.