Give an error message if reading in an incorrect Maybe with BinaryWith
Give an error message if reading in an incorrect Maybe with BinaryWith

ndmitchell/shake,ndmitchell/shake,nh2/shake,ndmitchell/shake,ndmitchell/shake,ndmitchell/shake,nh2/shake,ndmitchell/shake,nh2/shake,nh2/shake,nh2/shake