I voted to close but an error came with the following message:
this closure would result in the 'duplicate of' navigation only leading in a circle
So I flagged it for Moderator attention (it is still "active").
Now I have come back to the question and I see that it has been closed (another user could vote to close) and so two questions are closed as duplicate, each one pointing to the other.
Isn't it a bit strange? First, me not being able to vote but then another user being; then, having this circular duplication references.
PS: I tag it as "bug" although I don't know if it is. Please feel free to delete any tag that is not appropiate.