It would be great if Unreal did at least basic preflight checks before rendering or playback of a sequence (touched on this in a previous Feature Request) Currently there seems to be no preflight checking so Unreal will happy spend hours rendering incorrect views or rendering and never saving much to the frustration of users.
If a link for an actor, attach track, path or unresolved camera is found bring up an alert with the warning of unresolved links. No point in playing back or rendering a random view or missing key actors.
Before rendering the system should check validity of the path, name, disk unlocked, enough disk space, etc and likewise bring up an alert if any of those factors will prevent successful rendering.