1. In a building called Land_House_1W08_Brown, zombies cannot go through open doors, while they pass through other doors of this building.

1.1) The same problem with the building Land_House_1W10 (Yellow gray)

2. Also in the place where the doors are open there is an invisible glass texture.

2.1) The Land_House_1W08 building also has an invisible glass texture in the doorway, but zombies pass through these doors normally.