The partnership has 2 partners. One of them is a NY resident, the other is not. Partnership extension was filed with the IRS. Extension wasn't filed for NY.
It sounds like NY doesn't recognise the IRS partnership extension and an extension should have been filed for NY as well. (States should be obligated to accept the federal extension imho but imho doesn't matter). How much is the penalty? Is it $50 per NY partner or $50 per partner, no matter where the other partner and the partnership is located?