Hi,
I recently had a WPML database crash.
After reset, I got back all my content but I've lost languages informations and then links between original and translated content.
How can I get this to work again? even manually?
Are the language post/ page variations still existing? If so you can manually go to a page or post and on the right hand side where it says Languages, you can choose the language of the page/post and whether it is a translation of another page. See my screenshot attached - this will reconnect the translations.