I'm new to this site and mapping in general so I know very little about this stuff. I've created a couple rooms with the help of a tutorial I found on YouTube. I then saved the map and left for a while. When I got back and rebooted hammer all of my textures have disappeared and I am left with a couple of blue rectangles. I've tried to replace the textures but I couldn't get that to work. So could somebody please tell me how to restore the textures or prevent them from disappearing again. Thanks in advance.