When you are holding the property tool and you press C to copy a block. The walls showing the property will be stuck until you pull out the property tool and switch away normally. Nothing serious. Just a heads-up.
This bug is also a feature... since sometimes it's nice to be able to build while you can still see the property walls.
Quit finding these bugs. Only the community is supposed to help with that
. Even though this logic is wrong and It's nice to get bugs done with quicker... Meh.