Chesterfield secured sixth-place in League One at the end of the 2014–15 campaign, and went on to lose 4–0 on aggregate to Preston North End in the two-legged play-off semi-final. On 14 November 2016, majority shareholder Dave Allen resigned from his roles as chairman and director of the club. This signalled a crisis, and four days later a further four directors resigned from their roles. It was announced that Chesterfield was openly up for sale, and desperately needed some kind of investment in order to avoid administration. Mike Warner was installed as chairman on 19 November. On 8 January 2017, manager Danny Wilson was sacked, with Gary Caldwell being announced as his replacement nine days later. On 16 September 2017, manager Caldwell was sacked after three wins in 29 competitive games, giving him the worst win record of any Spireites manager. On 29 September 2017, club legend Jack Lester was appointed the club's new manager, bringing with him Nicky Eaden as his assistant and former caretaker manager Tommy Wright as a first team coach. In the Spireites first season in the national league they achieved a 14th-place finish.