Bob,
That looks as if one particular asset has a missing entry called "textures" in its kuid-table. The kuid-table is its list of dependencies.
To discover which asset it is, with TRS2004 you could use the standard Microsoft search facility to search the text within the files in the kuid folder tree for one of those other words such as imgadd. There may be numerous hits and probably only one will be offending. Sorry, I don't know if CMP in TRS2006 and later has a similar search facility. With TRS2004, the Trainz Objectz program might pick up the problem for you. Again I don't know whether TRS2006 onwards has any similar facility.
The other way to isolate it is to take a copy of the layout and start chopping things out until the problem goes away.
HTH, John