While trying to plan many of the inner walls inside my underground house, I got the following message: "[12:03:12] There is a fence or wall there. Action not allowed.". However, I can guarantee there are no fence or wall where I am trying to plan. The bug is easy to reproduce, you activate a hammer and you try to plan a inner wall inside my underground house, you should see the message appear. The Game Master named "Astarte" came to investigate the problem. He came to the conclusion that a building above ground above my house was interfering with my planning, he then asked me to post here. Here is a list of names to make it easier for you to investigate.
My in game name = Zariodan
Game Master that investigated = Astarte
Underground bugged building = Zariodan's bugged mansion
Above ground building that is interfering = Village trader
Settlement = Sanctuary
Server = Pristine
If you need more info, feel free to contact me on the forums or in game.
Have a nice day and thank you for a great game!