CRAFTBOOK-2764 - Reported by travelingdp

I am having a problem with users falling through chairs. This occurs whenever a user quickly double-right-clicks on a chair. The user sits and then stands immediately with their feet through the floor, causing them to fall trough to a lower level. This becomes a problem in certain buildings in which the basement area is restricted to op access. Users can get into restricted areas by exploiting this glitch.