Expiration of 2004 CBA. Owners want to lower the revune shares with players to increase profit and prevent the Players Union from owning part of the NHA. The Blades are most vocal, and Hans is explicitly in support of the players union becoming a partial owner of the league. Ultimately, the lockout was resolved with a 30% ownership share being granted to the Players Union, but the union did not get the demand of all former players being granted pension; only players who have played in the NHA/NHDA for 7 seasons or 600 games are eligible for NHA pension, even if their career ends due to work-related injury. See https://en.wikipedia.org/wiki/2011_NBA_lockout for reference.