In July I wrote a post about Validity of results. It was about a recent preprint pointing out an erroneous proof in an influential paper.
By chance I stumbled yesterday upon this question on MathOverflow: Extent of unscientific, and of wrong, papers in research mathematics. The question starts with a link to Kevin Buzzard’s slides of a talk he gave in January. I think his talk was meant as advertisement for the proof assistant Lean, but most of the time he was actually trolling mathematicians
To admit, I enjoyed reading the slides of his talk. So if you are up for some fun, you should do it, too!