Take for instance Wu-Yi Hsiang's suggested proof of the Kepler conjecture as a less controversial example. Quoting from https://en.wikipedia.org/wiki/Kepler_co

Take for instance Wu-Yi Hsiang's suggested proof of the Kepler conjecture as a less controversial example. Quoting from https://en.wikipedia.org/wiki/Kepler_conjecture https://en.wikipedia.org/wiki/Kepler_conjecture: "The proof was praised by Encyclopædia Britannica and Science and Hsiang was also honored at joint meetings of AMS-MAA." Which is followed, after a few sentences, by: "The current consensus is that Hsiang's proof is incomplete."