Yes, I did the translation of “Register Form” in “Form Editor”. I did also some translations in “General Settings”. These translations works very well.
Then I have translated some fields/messages in piereg-en_FR.po. I tried with the fields of “Login in” screen (Log In, Remember Me, Lost your password?, etc). I have also translated “This field is required”.
However login page is still on english.
I have removed all over file in Lang folder to keep only _FR mo/po files but nothing changed.