I've been posting about this in chat and filed tickets, so adding here in the hopes that eventually somebody can get around to this (I've been hearing it's an easy fix for months now)... This problem had existed through the 2016/Unity 5.3.7 builds, but was fixed with the first Unity 5.5 build (I think it was 170127). It returned in the early February build, and is worse in the 170222 build. While occlusion works for feet in boots, it is broken if the avatar is wearing stockings. Things looked like they were getting better (but still broken and reported) in the 0321 build, but in the 0331 desktop client they're completely broken again.