HI,
On Nostalrius PVE, after the item update, all skeletons (skeletal flayers, etc.) in WPL became immune to freeze effects. I checked the command log, and actually it is not even immunity. The freeze effect simply missing. Frost Nova does damage, but there is no sign of the spell trying to freeze the target, it looks like if frost nova wouldnt have a freeze effect at all. Frostbite however is in the log, but skeletals became immune to it. In the meantime freeze on every other creature just works well.