Error when create users

Warning shows me that:

“A non-numeric value encountered”

in this line:

$pass = $this->generator->randomNumber( $qty - 1 ) + $this->generator->randomLetter();

Context:

public function user_pass( $pass = null, $qty = 10 ) {
    if ( is_null( $pass ) ) {
        // By the way we should be using the WordPress wp_generate_password
        $pass = $this->generator->randomNumber( $qty - 1 ) + $this->generator->randomLetter();
    }
    return $pass;
}

PHP 7.4.21

• This topic was modified 3 years, 4 months ago by Aitor Méndez.