“The League of Chicago Theatres, the advocacy organization for approximately 190 local venues, is about to cease publication of Chicago Plays,” the program book created four years ago to replace the late, lamented “Stagebill.” Chicago’s extensive theatre community had hoped that a joint effort to produce a Chicago-specific program book would prove profitable, but as of this summer, the league owed $400,000 in back printing costs, and the project became unsustainable.