Errors

I am receiving the following error on my webpage:

Notice: Undefined variable: default in /home/—–/public_html/site/wp-content/plugins/responsive-header-image-slider/responsive_headerimageslider.php on line 258

On the backend page where I add an image, I am getting this error:
Notice: Undefined variable: rsris_slide_link_output in /home/——/public_html/site/wp-content/plugins/responsive-header-image-slider/responsive_headerimageslider.php on line 126

Webpage: http://ghfcc.org/site/custom-header/

Help?

https://wordpress.org/plugins/responsive-header-image-slider/