As part of our normal Drupal process we use both Display Suite (DS) and Conditional Fields frequently. While building out a site I ran into a very strange issue, when I was trying to output a field through DS it just wasn't showing up. I tried playing around with the formatters, label, etc. ... and nothing changed. So I fired up xdebug and took a look at the render array coming through and, yep, the field was in there. But '#access' was set to false.
Display Suite and Conditional Fields are hugely useful modules. There are some times when they don't always play nicely together. Here's one example of where they don't and how to fix it.