V4.5.4 – failed to open stream

Trying this out on a WordPress 4.5.4 system and get these messages in the Page Specific Stylesheets box. Would you let me know any fix/workaround?

Warning: include(__DIR__/templates/meta-box.php) [function.include]: failed to open stream: No such file or directory in /home/…/wp-content/plugins/page-specific-stylesheets/page-specific-stylesheets.php on line 98

Warning: include() [function.include]: Failed opening ‘__DIR__/templates/meta-box.php’ for inclusion (include_path=’.:/usr/local/php5/lib/php’) in /home/…/wp-content/plugins/page-specific-stylesheets/page-specific-stylesheets.php on line 98