Help:VE268
From TrainzOnline
Mesh file is unused in this asset: '$(FILE)'
This warning (trainz-build <= 500) or error (trainz-build > 500) is logged when an asset contains a mesh file which is not referenced in the asset's config.txt file.
This results either because the mesh file is entirely redundant, meaning that it should not be included in the asset, or because the mesh file is referenced indirectly from the config.txt of some other asset (eg. as a mesh library) without also being referenced in the config.txt file. In the latter case, the correct solution is to configure an appropriate mesh-table entry in the asset to reference the mesh, in the same manner that you expect other assets to reference the mesh.