Second, strictly speaking, this isn’t a PLP issue. Instead, it’s a PHP issue, and it can be fixed by upgrading the version of PHP that your server is running and/or adjusting your error reporting settings. (See this post from Stack Overflow.)
Finally, if you want to disable pagination from your 404 page, you’ll want to remove the wp_link_pages function from your theme’s 404.php file.
Please let us know if you have other questions/issues.
Page-Links Plus helps WordPress developers, site managers, and lay users paginate content easily & efficiently.