Why is my updated size chart page not linking in the footer?

[NikkiWhoops]

I've just updated my size chart page.

I have gone into the footer and linked this new page to the footer menu item, but I keep getting a 404 page not found when I check it on the site. I've checked it a couple of times but I can't get it to work.

I'm not sure what is going wrong. Have I missed a step?