Go to any Cockpit or tasklist URL that contains an engine name with a hyphen, e.g.
http://localhost:8080/camunda/app/admin/spring-engine/

A plain 404 is returned, regardless whether the engine exists or not. Even for engines that do not exist at all, the webapp login page renders at least.

(Tested with 7.2.0)

related forum post: https://groups.google.com/forum/#!topic/camunda-bpm-users/HsUkSouuSmg