Phaistos Disc
In 1995 independent linguist Steven Fischer, who also claims to have deciphered the enigmatic Phaistos Disc, announced that he had cracked the rongorongo "code", making him the only person in history to have deciphered two such scripts. In the decade since, this has not been accepted by other researchers, who feel that Fischer overstated the single pattern which formed the basis of his decipherment, and note that it has not led to an understanding of other patterns.