Change registration form validation message

Hello @rafi45678

UM currently does not have a hook to change that text but you can add additional validation to add that message, please try adding following code snippets with code snippets plugin or you can paste it to your theme’s functions.php file:

add_action( 'um_add_error_on_form_submit_validation', function( $array, $key, $args ){
    
    if( 'user_email' == $key ){
        if( get_user_by( 'email', $args[$key] )){
            UM()->form()->add_error( $key, __( 'That Email address is already registered', 'ultimate-member' ) );
        }
    }

},1,3 );

Regards,