Mixed language in admin backend

Ok I resolved the problem. It turns out I have mistakenly copied the .po files (fr_FR) of my theme into the /language folder and not /language/themes, so WordPress was picking the .po of my theme and not the one from wordpress.
I moved the po file to the themes folder and hit refresh on my website and I got a translation update. applied it and all is good now.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)