autoblog doesn't creat featured image

Hello, i have just installed the plugin Autoblog. I get an error by processing the feed to the blog.

Warning: preg_match() [function.preg-match]: Compilation failed: unrecognized character after (?< at offset 19 in /var/www/vhosts/rtv80.nl/subdomains/acc/httpdocs/wp-content/plugins/auto-featured-image/auto-featured-image.php on line 104