This question was marked as a duplicate of this question, but the latter has been removed from the system. So the reason "This question has been asked before and already has an answer." is no longer appropriate since there is no answer (or question for that matter). Regardless of whether the new question should be closed on other grounds or not, shouldn't the system have not the original question to be marked as a duplicate?
I'm with tcrosley on this, in that this deserves to be fixed. But an automatic fix may not be so easy to implement. The logic to prevent dead links like this:
- when question B is closed as a duplicate of question A, this should be recorded with question A. There may be several questions B
- when question A is deleted the list of questions B linked to it have to be reopened
Frankly I think this is too complex and requires too much work for what it's worth, as it won't happen that often; questions aren't deleted that much. So an alternative:
- when a closed question's link is dead, flag a moderator to reopen.