Complex sentence: Negotiators announced a final agreement to end the conflict and build a lasting peace on August 24,2016 with a referendum that was taken place on October 2,2016 which was unsuccessful after 50.21% of voters voted against the referendum although 49.79% voted in favor.
Split into simpler sentences: Negotiators announced a final agreement to end the conflict and build a lasting peace on August 24,2016. However, a referendum to ratify the deal on October 2,2016 was unsuccessful after 50.21% of voters voted against the agreement with 49.79% voting in favor.