Help:VE33
From TrainzOnline
Alias mesh meshname.im not found in dependency (<kuid2:##:##:#>)
This signifies that a mesh container specification, that includes a mesh-asset reference to a mesh, does not exist in the relevant mesh library.
Given this mesh-table container:
default
{ auto-create 1 mesh-asset <kuid:1234:5678> mesh meshname.im }
the message would signify that meshname.im is not present in the dependency <kuid:1234:5678>.
Note: When repairing old assets to newer build versions, it is possible that referenced mesh-assets, including built-in assets, still use the progressive mesh format (.pm). In that case try examining the referenced asset to see what format is used.