Flamingo nXt 5 is an update to Flamingo which integrates with the built-in rendering features in Rhino 5. This is currently a work in progress version.
You can join the technical discussion about this beta here: Flamingo Discourse Forum
This version of Flamingo features an interface which is integrated with the Rhino 5 rendering tools. This made several necessary changes to the rendering interface. At this time it is important to find the Flamingo interface when first starting up Flamingo: