UML14 — transition is simply never enabled

Maybe this is a stupid question. But I could not find an answer ... A transition is not required to have a trigger. If the source of the transition is a composite state, its triggering is described by the rules about "completion transitions". But what happens if the source is just a simple state: It would seem that the transition cannot be considered as a "completion transition", but at the same time, the transition never satisfies the rules about "enabled transitions". Hence it woulds seem that the transition is simply never enabled. Is this interpretation correct? If so, it this behaviour really intended?

see above