A foil to the open-problems corpus. Where that catalogue asks what is still open, this one asks the sharper question: what is widely treated as closed but isn't.
These are the false negatives of the humanities — problems filed under "solved" in textbooks, survey courses, and popular accounts, where the consensus is either a teaching simplification, a fashion, a corpse still being cited, or a genuine consensus that new evidence has since cracked.
The status taxonomy: