If you begin exploring Trainz as a building tool, crafting or modifying a route, you will indubitably end up facing the learning curve of fixing assets. Asset fixing is something of a misnomer—assets need fixing because they have become out of date relative to updates in the game engine's data needs. Various techniques have been adopted requiring different data, or a difference in the way data is organized. Most of these changes are handled automatically within the software. When they cannot be, they generate an error, a good thing. Having an error appear in an asset is far better than having a flaw in an asset create a program crash.
Trainz user PEV has written some tools for fixing content.
Note many texture faults can be fixed by recreating the .im file with PEV's PM2IM program, use it standalone then point it to the asset folder.
PEV has a tool for creating shadows, called QuickShadows. QuickShadows can be downloaded here: *
Engine spec <kuid:35837:51002> can be replaced by <kuid:44090:51016>