on graph draw the link from some page to start state: since start state cannot be target, the link doesn't appear on diagram - for user, creation fails silantly; visually the result is the same for situations when the link is dropped to empty diagram space and to invalid target. But in code the transition to this element is created in the last case.
It would be nice to provide the different cursor shapes, for example, for 'valid target' and 'invalid target' states. Or at least don't create the invalid links in code.