When loading a counter example for a liveness property, it used to be the case that the cyclic part of the
trace could be unfolded. This is no longer the case.
Due to new features introduced in the language (select on edges, priorities,
etc) this can no longer be implemented in the GUI without help from the server.
I doubt that this feature will be implemented before 3.6 is released. Decreasing
priority to P3.