In another thread they clarified that the fix was to prevent more armor from dropping without the slot. The armor that has already dropped however is still being investigated. No ETA on a fix so it might be worth just getting a new armor piece.

I guess so. It's just annoying because you're only high enough level to quickly farm master content for part of the season, so it's not like you can just do it anytime you want. I'm going to knock out the new dungeon on master today, so hopefully I'll get a few pieces to replace it. I'd saved perfect rolls of chest pieces and all four class items for all three characters, and like half of them have the slot missing. That's a lot of work to replace.

No I get it, especially with the Avarice dungeon being 1590 last season. I'm hoping the fix comes soon because I have some friends in the same situation, but they saying goes [i]"hope for the best but expect the worst"[/i].