Error login message


I’m taking care of a website which was built by someone else.

I have an issue with Login functionnality : if a user tries to log but make a mistake in a filed, try to create an account but the EMail is already used… The concerned fields are highlightning but there is no message to tell the user what’s going on.

Despite of the user.module seems to be good ( I see the concerned functions), where can these message be switch off ?


Drupal version: