missing <kuid:138423:112129>

A Google search revealed that this has been a "missing asset" for at least 10 years.

This thread, https://forums.auran.com/trainz/showthread.php?111228-Missing-Kuid, might provide the answer but the link to a 3rd party web site it gives is now about 6 years old so the site may no longer exist. This is the main reason why I simply delete any downloaded assets, including routes, that contain missing assets, life is simply too short.
38 links on TKI...

With only a single version of Trainz registered and, so far, only 2 posts to his name, the original poster probably doesn't know what TKI is or where to find it. So more info would be appreciated.
Had a look....... and downloaded <kuid:477026:100401> Amtrak 60' MHC #70002 your missing kuid is not referenced in the config other than an entry in the kuid table, deleting it from the kuid table solves the problem, just tested in TRS19 after deleting that kuid.