I don't see Network Connect, but I do see a line that says "Host Checker Not Required"
You may have an incorrect bookmark, or you may have attempted to access the VPN by starting to type cuvpn.colorado.edu in your address bar but selected a longer address recommended by your browser.
You should only access the VPN by opening https://cuvpn.colorado.edu. This is the address that should be specified in any bookmark you've made for the VPN.
I tried to access my custom VPN but got the standard version
Make sure to press Enter, or the "Go" button, in the "Sign In" line of Network Connect after entering the custom VPN URL. Network Connect acts like a mini-browser to get to the actual sign-in page, and you have to tell it to go to the URL before you can login there.
Read more about connecting to the network with a Custom VPN.