Error Message

Maybe someone will know what this error message means…whenever I upload/install a new theme, or run updates on plugins, I get the following message:

Warning: Missing argument 3 for wpseo_upgrader_process_complete() in /home/content/35/11734735/html/wp-content/plugins/wordpress-seo/inc/wpseo-non-ajax-functions.php on line 259

Everything updates/uploads just fine–all usable, no glaringly weird glitches. Just that the message is there every time. This just started a couple of days ago. If anyone knows what it is, if I should be worried, or how to get it to go away, I’d appreciate the information. Thanks!

My site: http://wrightoutloud.com/