The new Media Translation plugin, which comes with WPML 4.0, has a number of design mistakes, which are causing problems. We’re fixing them right now and we’ll have an update this week.
Basically, our left hand was out of sync with the right hand. So, we removed functionality from one plugin and forgot to include it in another.
Before WPML 3.9, the main purpose of WPML Media Translation was to allow images to appear in all languages. If you created a post in one language and uploaded attachments to it, you’d want these attachments to appear in all languages. This is useful for [gallery] shortcodes and the featured image.
As of WPML 3.9, this duplication isn’t necessary anymore, with the new Display as Translated. So, we removed that functionality from Media Translation. The problem is, we didn’t notice that the config file in WPML forces images to be “not translated”. So, our grand design produces something that doesn’t work at all.
Of course, we should have noticed this a lot earlier.
Anyway, we’re right now working on an update for both WPML core and Media Translation. This update will allow to show images on translations without needing the Media Translation plugin.
You will be able to upload images to the page that you create in the site’s default language. All its translations will show these images. This includes featured images and galleries.
We thought that if you’re not using Translation Management, you have no use for Media Translation, so we blocked it. We temporarily re-enabled Media Translation for clients with “Multilingual Blog” accounts, so you can continue downloading Media Translation. Once we release WPML 4.0.3, the Media Translation plugin will really be completely unneeded for you.
We want to make sure that we’re covering all issues related to media translation. If you’re seeing anything else, please add a comment. It’s best to report first in our support forum and then add a comment here with the link to that ticket.