Slide In Error for class Wdsi_Options

Hi, I’m getting this error message on all pages now with Slide In. There are other ones below it related to the theme as well, but this one is the first that shows up…

procenter.staging.wpengine.com

Strict Standards: Redefining already defined constructor for class Wdsi_Options in /nas/wp/www/staging/procenter/wp-content/plugins/slide-in/lib/class_wdsi_options.php on line 9