I just upgraded 4.12 -> 4.2 and now I get this error everytime I try to publish "category monthly archives"

CODE
Can't locate object method "id" via package "Reading Now" (perhaps you forgot to load "Reading Now"?) at lib/MT/ArchiveType/Date.pm line 57.


'Reading Now' is one of my categories, so I dont see why it would need to be loaded. Is anybody else having this problem or am I just lucky?