Redirection function has storpped working with recent WordPress Update

Hey, this plugin did exactly what I wanted with no unnecessary bells or whistles attached, but after the recent updates to wordpress, I am noticing this plugin no longer appears to be redirecting users properly.

I was wondering if anyone else was having a similar problem or if something in wordpress has recently broken this plugin? Any help would be greatly appreciated!

The page I need help with: [log in to see the link]