Description
The option to select specific category in Product Coupons and Sales Discounts brings up an empty page.
 
Solution
http://www.viart.com/downloads/win_select-4.2.1.js.zip
 
Download the file above and extract 'win_select.js' in the /js folder of your shop replacing existing file. Please do not forget to make a backup copy of the current file in case something goes wrong.