INSTRUCTIONS: To Use Our Visual Custom OTF Knife Builder, Click On The Seven Icons To The Left Of The Knife Preview Window To Reveal The Available Options For Each Component. Then Click On The Component Option You Wish To See. Please Allow A Few Seconds (Load Time May Vary) Once An Option Has Been Selected For The Visual Change To Occur In The OTF Knife Preview Window. When You Are Happy With Your Custom Design, Simply Add To Cart And Proceed To Checkout.
Looks like you're trying to access the configuration page directly. This page can only be accessed by clicking on the Build your own button from the product or the shop page.