Owner and Tenant Rights in a Cooperative

[Adam Leitman Bailey]

A co-op owner purchased her unit in 2005 and has been subleasing it to the same tenant since 2011. The co-op board recently passed an amendment to the bylaws that states an owner cannot sublease a unit for more than two years, and it applies retroactively. The board is forcing the sublease tenant to vacate in two months, despite having a lease that runs another seven months after that. Does the owner or tenant have rights in this case?