The Elamite language of the ancient Elam Empire in what is now Iran, is one of the best known undeciphered languages. A French scholar now claims to have deciphered its script, neck and neck with Sumerian and Ancient Egyptian as the oldest known scripts in the world that are truly proper languages and not just a collection of select symbols. I'll try to confirm the find further as time allows. The report appears to be based upon a conference presentation rather than a peer reviewed journal publication.
François Desset took ten years to decipher linear Elamite and its mysterious symbols inscribed on tablets discovered in 1901.Writing was desperately seeking reader. Linear elamite, discovered on clay tablets in 1901, has so far remained a mystery. Until the archaeologist François Desset finally deciphers it, after ten years of research. A discovery relayed by Science and the Future . This phonetic script was used in a kingdom that flourished between the 3rd millennium BC and the 2nd millennium BC. It was discovered in 1901, when archaeologists discovered mysterious symbols on vases and several objects buried under the ancient site of Susa, Iran. 4,500 years ago, the country was called Kingdom of Elam, hence their choice to give this name to writing.