There have been more than a few users who have wondered why resource "x" won't allow highlights. The solution has always been: "Please check the resource's visual filter menu to make sure the note document and master switch are turned on."
Is there some sort of bug or unintended consequence of a change which is causing either the note document or the master switch to be turned off? Most users come back reporting that they didn't remember turning it off... Which leads me to wonder if they turned it off in the first place. [:s]