First if you use an actor like a truck you need a second waypoint, simple set one near the first or look into artillery they don't need a waypoint or into static object there also trucks you can use without need of a wp.
The building '0_bld' has unlinked hooks has to do with larger industrial buildings (these who use more than one part to finish), it's a bug we can nothing do against. Only solution is not to use them.