Installing v4 fail

Ok I make backups of my site, uploaded the latest version 4.1, I have access to my wp-admin, I deleted any shortcode in the HOME page, and I got this error:

Fatal error: Can’t use function return value in write context in /home/USERXXX/public_html/wp-content/themes/fundingpress/header.php on line 165

and line 165 in header says:

<?php if(empty(get_the_author_meta(‘last_name’, get_post_field( ‘post_author’,$post->ID ))) && empty(get_the_author_meta(‘first_name’, get_post_field( ‘post_author’,$post->ID )))){
echo esc_attr(get_the_author_meta(‘login’,get_post_field( ‘post_author’,$post->ID )));
} ?>

What am I doing wrong?