I run a multi-author website and many of my users are forgetting to set a featured image for their post. This is a big problem as my theme depends highly on featured images to keep a consistent feel throughout the site.
I've found a plugin that allows for a default featured image to be set if the user doesn't set one but this is far from perfect.
Is there anyway to have an error message pop-up when the featured image is not set and the user tries to publish, or potentially disabling the ability to publish a new post until a featured image is assigned?
Ideally I'd like to find a solution that pops up before the page is reloaded, to limit the frustration of the user/avoid unnecessary steps and time wasted reloading the page.