Warning: array_merge_recursive(): Argument #2 error

I have just found a error on one of my sites , jigshop is v1.9.2 , all plugins are current but i see this error at the top of the screen. Does anyone know a reason or a fix

thanks
ian

Warning: array_merge_recursive(): Argument #2 is not an array in /home/username/public_html/domain.com/wp-content/plugins/jigoshop/classes/jigoshop_options.class.php on line 137

Warning: array_merge_recursive(): Argument #2 is not an array in /home/username/public_html/domain.com/wp-content/plugins/jigoshop/classes/jigoshop_options.class.php on line 137

https://wordpress.org/plugins/jigoshop/