Rise: Problems publishing localised courses

Luck​  One quick tip, never edit a course after localising. Make course duplicates to localise. There's a couple of giveaways in your post. You say you can export the English version, and the reason for this is that it uses the original metadata. The way Rise localises is to create language specific metadata layers on top of the base course. This is why I asked if any edits had been made as this can corrupt the metadata (usually an in course quiz or scenario block as the logic based blocks code slightly differently and can easily break references). The reason your colleague's export a week ago succeeded is likely because the corruption hadn't been introduced yet; most likely by a subsequent edit (but could be other causes).