Trying to cast a delete vote on https://math.stackexchange.com/questions/204765/show-the-negative-derivative-of-a-function I receive the message
When I view linked questions, I find there is just one question. But I can't vote to delete it either, since it was merged into the above one, and therefore locked.
: This is a feature that SE introduced about a week ago.
: The sidebar says "2 linked questions", due to another bug that I reported last year.