For some reason I'm only allowed to get the essence quests for the head, gauntlet, chest, class item, LMG, and Auto Rifle. I've done every one of these before when they were current content, and now the rest is locked saying "Can only hold one at a time" despite not having them in my quest list. While typing this, I abandonded the Essence of Failure auto rifle quest, and now it is also locked saying the same as the others.