The issue is definitely due to the installation of OZx library v4.0 being installed on my system and only a few of us have it. Dieter does and you can see that he also saw the object I used fine on his system while others here didn't see it. So, I"ve removed that object, replaced it from what I hope is a tunnel object from one of the older OZx libraries.
Doug just got the latest version for Kwatna River uploaded. Version 2.0 should address that missing object so please delete your previous version and replace it with v2.0 ASAP. Then report back here and let me know if that fixed the missing object problem.
I also added a few more objects to the coal mine to liven it up a bit.
Thanks and sorry for the confusion,
Brad