The official statement is here: https://www.reddit.com/r/RimWorld/comments/1lvstmy/important_psa_from_vanilla_expanded/

But to quote it so you don't have to bother looking: "Vanilla Furniture Expanded - Security will not receive an update for now, as we're in the process of remaking the mod. The remake will release when finished. Do not use the 1.5 version of Vanilla Furniture Expanded - Security on 1.6 save, as your save will break."