hit1205

Thanks, so it's a feature, not a bug. In the thread, I saw this: But it seems Mojang does not think it as a bug: https://bugs.mojang.com/browse/MC-378 They just detect the block above the chest that is transparent or not, no matter it's normal or upside-down slab/stair, and Dinnerbone resolved the issue as "Works As Intended", so I don't think they will "fix" it

This problem happens in the latest version Forge 11.15.1.1763 (and the recommended version 11.15.1.1722, too) Chest under stair (B) or lower slab ©: cannot be opened Chest under upside-down stair (A) or upside-down slab (D): can be opened as normal (Tested without any mods) In the vanilla Minecraft 1.8.9, all four chests can be opened as normal. My fml-client-latest.log: http://pastebin.com/embed_iframe/DapfzFrC