When enchanting any boots to frost walker 2 nothing comes out

Put the summary of the bug you're having here

What I expected to happen was...:
when I enchanted the boots I thought I was going to get frost walker boots

What actually happened was...:
when I clicked on the final slot the BOOT WERE GONE!!!!!!

Steps to Reproduce:
1. go to an anvil
2. ...use the frost walker 2 book then put in the boots in the second slot
3. ...then click on the final slot and...GONE PLESE FIX!!!!!!! AHHHHHH!!!!!!!