Complex sentence: During the 2014 festival, college students, the majority not enrolled at Keene State, caused riots in nearby neighborhoods, resulting in the city council declining to grant the festival's sponsors a license to hold the event in 2015.
Split into simpler sentences: During the 2014 festival, college students, the majority not enrolled at Keene State, caused riots in nearby neighborhoods. As a result, the city council refused to grant the festival's sponsors a license to hold the event in 2015.