No the code I gave you is just link and couldn’t have caused this. I also checked it in our own demo before I gave it to you.
Do you have any plugins installed or did you make any changes to the code? You can try removing the plugins via ftp. You can find them under wp-content/plugins/. You can also do the same with the theme if you’ve made any changes. Be sure to create a backup so you can place it all back when you’ve found the error.
Hope this helps!