[Plugin: Related Posts Slider] Warning message in multisite

in my main site nothing message, but after add new site, in new site gives me this message in front..
Warning: extract() [function.extract]: First argument should be an array in wp-content/plugins/related-posts-slider/includes/cf5-rps-slider-formats.php on line 13

http://ww.wp.xz.cn/extend/plugins/related-posts-slider/