"no Permission" Doors And Chests

I know that for some areas, you can't go in because it's only for a quest, but with some areas, like the entire desert of Almuj, I can't open any doors or chests, because I get the message, "You do not have permission for this area". If I don't have permission, why can I enter the area in the first place?
I started having this problem when I changed my game to 1.8.9. Could this have anything to do with it?

 

Probably a bug.

 

Use your hand to open things. It's because the item you're holding is a block (retextured) and the game thinks you're trying to place it.

 

are you trying to open them with your weapon in hand? if so, just switch to an empty slot

 

This, right here, is THE reason that you are experiencing this error. Try switching to another item, or to an open hand. No, there is nothing that can be done to fix this, as it is a normal MC core mechanic.

 

It is an error when you are opening the door with a slab or something not full block.
Example will be the multiple elements wand

 

Thank you!
I am using Detlas's Legacy, which I know is a wooden slab. This will help a lot!